Alcatraz Island is one of the most infamous prisons in the world. It has has been said that it was impossible to escape from this prison due to the high security combined with the fact that it is located on an island in the San Francisco Bay, which is known to be infested with sharks, have fast moving currents, strong winds, and for parts of the year, very cold water.

The prison was first built in 1850 as a military fort, but in 1934 it was converted into Alcatraz Federal Penitentiary, where it housed some of the most notorious criminals of the time, including Al Capone. It was finally closed on March 21st, 1963 because it cost too much to run. Today, tourists can visit the prison to see what life was like on ‘The Rock’ (it’s nickname). Visitors may not be able to go here much longer (or at least not voluntarily) as there is some talk of reopening the prison by President Trump, but that isn’t likely to happen anytime soon.

For many people, the big question about this prison revolves around whether it was truly impossible to escape or not. While lots of people housed in this prison likely thought of trying to escape, there are only three who may have succeeded. And the word may is doing a lot of heavy lifting, since it is very unlikely. The fact is, however, that three prisoners (Frank Morris and John & Clarence Anglin) did manage to get off of Alcatraz island and their case is still open even though it happened back in 1962.

In all likelihood, the three died in their escape attempt while trying to get from Alcatraz to the mainland, but in 2014, researchers found that it was technically possible that they survived. First, let’s look at how the escape went down.

For months before their escape attempt, the three (plus Allen West, another inmate who decided not to join them on their escape) worked to widen the ventilation ducts below their sink. They did this using sharpened spoons as well as a makeshift drill that they constructed using the motor of a vacuum cleaner. Once they got the shaft wide enough to get out of their cell, they placed papier-mâché likenesses of their heads on their pillows and crawled out.

The escapees did everything they could to keep their escape a secret, including using real human hair to make the wig for their fake heads. The rouse worked as the guards did not discover that they were missing until the following morning when they checked the cells of all the inmates.

Getting out of their cell and onto the shore of the island was just the first step of their escape. They still had to cross the waters of the San Francisco Bay. To do this, the three used a raft that they made from dozens of raincoats stitched together. The broken raft was found in the bay, however, so it seems that it did not stay together long enough to get them ashore on the mainland. Depending on how far the raft made it, and how good of swimmers the three were, however, it may have been possible for them to swim the rest of the way.

The research project ran computer models using tidal records of the San Francisco Bay on the night of June 11, 1962 to determine how likely it was that the trio managed to survive. Running 50 simulated boat launches at various points along the shore of Alcatraz Island for each 30 minute period ranging from 10PM to 4AM, the researchers found that it was indeed possible that the escapees survived to reach land. Possible, but not likely.

These prisoners would have had the best possibility of survival if they left sometime between 11PM and midnight based on the tides, currents, and other factors. Once they set sail, they would have had to paddle hard to get as far as possible before their makeshift boat came apart, and then they would have had to swim the remaining distance. This would have been no easy feat given the strong currents. The average water temperature at that time of year is just 58.6 degrees Fahrenheit, which is much too cold for comfort, but wouldn’t cause immediate hypothermia.

So, yes. It is possible that these three prisoners may have escaped the inescapable prison. The fact that a lot of things would have had to go perfectly right, and that there has been no sightings of them in the past 60 years, however, makes it seem incredibly unlikely.

If you thought that was interesting, you might like to read a story that reveals Earth’s priciest precious metal isn’t gold or platinum and costs over $10,000 an ounce!