In January 2010, a massive earthquake struck Haiti, killing upwards of 100,000 people. In 2005, a similar sized earthquake hit Pakistan, killing 86,000. In 2004, one the largest earthquakes ever recorded was a massive 9.1 magnitude quake that hit in the Indian Ocean, causing a massive tidal wave that would ultimately lead to the deaths of an estimated 230,000 in India, Sumatra, and Indonesia.

It’s been over a century since North America has seen an earthquake on such a massive scale, but seismologists agree that one is coming. The San Andreas Fault, one of the largest known fault lines on the globe, has been slowly building pressure over the past 100 years. The lower portions of the fault, near Los Angeles in particular, haven’t seen a major quake in over 300 years. It’s only a matter of time until the massive tectonic plates slip and let loose what experts call “the big one”.

It’s been so well documented that they actually made a movie about it with the same name. In terms of silver-screen fun, San Andreas does a decent job of telling the story of a series of massive earthquakes that destroy much of California, but we preferred to ask ourselves what would really happen if San Francisco were to be wiped out by a major earthquake the likes of which the world has never seen?

Here are 15 things that would happen if such a quake were to strike San Francisco today.

15. Loss of Iconic American Monuments

We’ll start with the obvious, in that San Francisco is home to quite a few American monuments to engineering. The Golden Gate Bridge, Alcatraz, the Castro Theatre, Fisherman’s Wharf – all of it would be gone if a nine-point-whatever magnitude earthquake were to strike the historic city.

While the loss of American history would be priceless, the damage in terms of dollars would be so great it’s difficult to estimate. The most damaging earthquake in modern history, the 2011 Tōhoku earthquake in Japan, cost well over $200 billion in damages by the time the dust had settled and most of it caused by the resulting tsunami. Japan had invested billions in 40-foot-high seawalls to prevent tsunami damage, but even with their preparations, the earthquake and proceeding waves destroyed over 45,700 buildings.

San Francisco hasn’t spent nearly as much on precautions as Japan, and the damage would likely be far worse.

14. Many Celebrities Would Die

San Francisco and the greater Bay Area are home to tons of famous people and celebrities. Names like Nicolas Cage, George Lucas, Sean Penn, and Sharon Stone all call San Francisco their home, and would likely be around when the next major earthquake strikes. And since it’s really hard to build a safe shelter from earthquakes, I doubt any of them have invested in any kind of personal protection.

More than celebrities would be the loss of great musical talents. Bands like Green Day, Metallica, and Third Eye Blind, as well as solo artists like Neil Young, Carlos Santana, and Chris Isaak all call the Bay Area their home. Provided they’re not on tour when the quake strikes they could all get caught in the resulting chaos and fall victim to the potential natural disaster.

13. Outpouring of Support from Celebrities That Survive

If there’s one thing that we can all count on when times get rough, it’s that American celebrities will all get on camera and ask the rest of the country to donate to relief programs following a natural disaster.

After Hurricane Harvey struck Texas and the Gulf Coast, Tyler Perry, Kevin Hart, Hilary Duff, Miley Cyrus, Leonardo DiCaprio, Sandra Bullock, Selena Gomez, and dozens more all took to social media to announce their donations to disaster relief programs and to ask the rest of the country to pitch in their fair share.

For the celebrities that survive, you can be sure that they’ll ask for donations to the victims of the Great San Francisco Earthquake mere hours after the dust settles.

12. The Death Toll Would Be In The Hundreds Of Thousands

San Francisco proper is home to about 900,000 people. The surrounding Bay Area is home to roughly 7.7 million people. If a major earthquake were to strike in the heart of downtown San Francisco, the loss of life would be on a scale that America has never seen.

A 9.1 or higher magnitude quake that hits anywhere within San Francisco would topple buildings, crumple highways, and split the earth. Anyone caught inside during such a quake would be highly unlikely to survive. Fires would break out as gas mains cracked, further increasing the body count. All 900,000 people would be at risk.

If the quake were to be so bad as to kill everyone in San Francisco, it would double the amount of Americans killed in World War II.

11. The Entire Western Seaboard Would Lose Power

Infrastructure in North America has been considered inadequate and antiquated for decades. Roads and highways are the most high-profile areas requiring renovation, but so does our aging electrical grid. If San Francisco were to suddenly disappear beneath a massive quake it would likely take out power for the entire state, and quite possibly the entire Western Seaboard.

There are no power plants in San Francisco, so it won’t be due to a sudden lack of power. Rather, it would be due to such a massive disruption of the power grid that it would trip breakers all along the system, as the expectant load of a massive metropolis disappeared and the remaining power lines all took on way more electricity than they could manage.

It’s not quite as sexy as the sight of Hoover Dam cracking open, but we can forgive Hollywood their fancy disaster scenes. 

10. Tremors Would Be Felt As Far As San Diego

California is big. Really big. So when a massive earthquake can be felt as far as San Diego, 500 miles away, then it is a truly massive earthquake.

It’s certainly possible. The largest earthquake recorded in modern history, the Valdivia earthquake that struck Chile in 1960, was felt all along the coast from Chiloé Island to the city of Talca – a distance of nearly 600 miles. It was even felt in villages in neighboring Argentina, where it shook residents awake in the dead of night.

However, the most terrifying thing about such an earthquake is how it would not likely be alone. Much like the movie San Andreas, and much like the Valdivia earthquake that struck Chile, a big earthquake is almost never alone. Several foreshadowing earthquakes, called foreshocks, would likely strike all along the fault, with Los Angeles being a prime target due to its proximity.

9. Could Last As Long As 10 Minutes

Much like my bedroom performance, most earthquakes that have been recorded didn’t last very long. The average duration of a tremor is between 10 and 30 seconds. Those 10-30 seconds might be terrifying (again, much like my bedroom performance) but they’re over and done with relatively quickly.

Things are different when it comes to massive earthquakes such as the one that struck Chile in 1960. That tremor lasted for a horrifying 10 full minutes. There are very few buildings that are designed to survive a 9+ magnitude earthquake for over 5 minutes, let alone 10. That kind of shaking is enough to cause even the most well-designed skyscraper to topple over, and San Francisco has many of them.

8. Tsunamis Would Reach Around The World

While an enormous earthquake can be plenty damaging on its own, by far the more worrisome and devastating effect of an earthquake is the tsunami that often follows. Quakes that take place in the ocean or near a coastline can trigger a tidal wave that can cause massive flooding and further loss of life.

They also don’t necessarily have to strike the same place as the earthquake. The Valdivia quake was so huge that the tidal wave it produced traveled around the globe, striking as far as Japan and the Philippines. Hawaii was also struck, with Hilo country being swamped by 40-foot waves that killed 61 people.

Waves that struck Japan were still recorded as being as high as 35 feet.

7. The Internet Would Be Totalled

There’s a very important place in the San Francisco Bay Area, at least, in terms of the internet: Silicon Valley. The place is home to many giants of the information age, including Apple, Adobe, AMD, eBay, Intel, Cisco Systems, Oracle, Yahoo!, IBM, and many, many more.

Consequently, these businesses all have important infrastructure related to the internet, and if they all went down, it would be disastrous for the wider internet – certainly in North America and possibly the world.

What’s worse, a lot of data is being stored in Silicon Valley server farms and if they all disappeared it would mean the loss of untold petabytes of info. A lot of that info might have something to do with the next item on this list.

6. Stock Market Would Crash

San Francisco is the sixth largest financial center in the world. There are dozens of Fortune 500 companies that have important offices there and is home to the Pacific Exchange, one of the largest stock exchanges on the Western Coast.

If a massive earthquake were to strike San Francisco, all these companies would be heavily affected. Besides the cost to those companies that are headquartered there, much of the West Coast’s financial infrastructure as it relates to data is housed in beautiful San Fran. If all that data goes, it would mean market chaos to rival the 2008-2009 housing bubble crash.

How far the crash would extend is anyone’s guess, but a lot of Asian and Pacific markets have strong ties to the San Francisco market.  So much like the tsunami, the ripples of financial calamity would be felt around the globe.

5. California Would Move Several Feet

Something that isn’t often discussed when it comes to earthquakes is the simple fact that the earth moves. And I don’t mean in the violent back-and-forth motion that signifies a tremor – I mean in the lateral movement of the land itself.

Even without an earthquake, the land is constantly moving. Along the San Andreas Fault, the two sides of the divide move opposite each other about an inch a year. During an earthquake that movement speeds up quite a bit.

The 2011 earthquake that struck Japan actually caused the main island of Honshu to move 8 whole feet closer to the US coastline. If a similar quake were to strike San Francisco we could expect it to move a few feet closer to San Diego – with disastrous consequences of course.

4. Aftershocks Could Take Weeks To Settle

As I mentioned earlier, large earthquakes never happen alone. Smaller earthquakes often precede the big one well before it strikes, with smaller aftershocks happening for weeks before things settle down.

In Chile, the Valdivia earthquake was preceded by several smaller shocks, although still quite large relative to other earthquakes. The first one happened a day before the largest tremor, which was a mere 8.1 magnitude shock (to put that in perspective, the earthquake that struck Mexico and toppled buildings last week was a 7.4 magnitude tremor). The big one then hit Chile the following day, and it was two weeks before the aftershocks finally went away.

If the San Francisco Quake is anywhere near as large as the Valdivia quake, the Bay Area would be trembling for weeks.

3. San Francisco Peninsula Would Turn Into An Island

San Francisco currently sits on a peninsula that reaches into San Francisco Bay. A large enough earthquake would not only move the entire bay several feet, but the resulting tsunami would very likely flood the lower sections of the city and cut off the peninsula, forming San Francisco Island.

It’s not without precedent. In 2013, an earthquake off the coast of Pakistan actually created a brand new island from nothing. According to experts, trapped underground gasses were dislodged during the quake, and when they escaped they brought a load of mud and rock with it. It’s just one example of how a large earthquake can totally change the landscape and forever change coastlines, like the one San Francisco sits on.

2. A Refugee Crisis The Likes Of Which America Has Never Seen

With a total of over 8 million people, if a massive quake were to strike San Francisco and the Bay Area it would leave millions of people homeless and without power. After a few days, food would become scarce. Water lines would be damaged, making clean water hard to find. Medications would be lost, and people in hospital or on life support would be in dire need of immediate evacuation along with hundreds of thousands of injured residents.

The United States hasn’t seen a crisis of that magnitude in its short lifetime. The amount of food and water and supplies that would need to be mobilized would strain FEMA to its breaking point, and it the current political climate it seems congress wouldn’t be able to respond quickly enough to prevent thousands more from dying in refugee camps.

We could hope for The Big One to never come, but every year it doesn’t just make its potential for utter disaster even stronger.

1. The POTUS Probably Wouldn’t Care

Let’s be honest: the POTUS has been a vocal opponent of California, and San Francisco in particular, ever since he took aim at Sanctuary Cities.

During his campaign, he singled out San Francisco as a particularly egregious violator of American immigration law for allowing illegal immigrants to stay in their city, the definition of a so-called Sanctuary City. Following his election, the San Francisco board of supervisors made several resolutions that were greatly at odds with the President’s rhetoric, such as resolving that Climate Change is real and that San Francisco will remain a Sanctuary City at all costs.

This, combined with the fact that San Francisco voted heavily against him during his election, would lead anyone to believe that the capricious President wouldn’t bat an eye if the entire city were wiped out.