During the warmest months, the San Francisco Bay averages around 60 degrees Fahrenheit. Even though the human body can survive such temperatures, the rough waters and rip tides are no match for humans. There were 14 different escape attempts while Alcatraz was open. Most of those attempts ended the same way.
The first attempt in 1936 involved inmate Joe Bowers who was working as a trash incinerator. He started to climb the perimeter fence at the end of the island. A correctional officer stationed in a guard tower gave him fair warning to climb back down. Bowers refused, was shot, and fell to his death. Inmates made it a little further during the second attempt.
In December 1937, Theodore Cole and Ralph Roe somehow made it through the iron bars of their cell. A terrible storm was raging outside and the bay's currents were stronger than ever. The escapees made it to the bay and were believed to have been swept out to sea. The two were missing and presumed dead. Then, 25 years later, three men made it further than anyone up until that point.
On June 11, 1962, brothers John and Clarence Anglin, along with fellow inmate Frank Morris, devised an intricate escape plan. Using homemade drills, false walls, and the heads of dummies, the three men exited their cells with no problem. They made it to the roof before climbing down a drainpipe and to the water where they boarded a homemade raft. The three were presumed dead until 2013.
In 2013, the San Francisco Police Department received a mysterious letter. The man, claiming to be John Anglin, wrote about surviving the escape. He claimed the three inmates made it to shore and wound up spending their days in Seattle under different names. The aging convict detailed his escape and current status.
He stated, "My name is John Anglin, I escape (sic) from Alcatraz in June 1962 with my brother Clarence and Frank Morris. I’m 83 years old and in bad shape. I have cancer. Yes, we all made it that night but barely." He went on to make a plea to authorities.