Why Alcatraz is still Unsolved Today
Authorities are still puzzled about the prisoner's escape from Alcatraz. The FBI was able to piece together the plan of the prisoners based on the evidence that they collected including the tools they used, the missing items, and the grill from the ventilator that was removed that revealed where the escaped from. The bodies of the men were never recovered to prove that they did not achieve their goal of reaching land. However, the FBI believes that the survival of these men was unlikely for a number of reasons.
First, the freezing cold temperature of the Bay and the rough currents that pursued the night of the escape suggest that the successful attempt of the prisoners to swim from Alcatraz to Angel Island was unlikely. In addition, no thefts of cars or other materials were reported that suggest that the man successfully made it on land and continued their plan to survive. Finally, no evidence came forward during the FBI's investigation to suggest that the men were living anywhere.
The FBI officially closed the case on December 31st, 1979 despite fully solving the mystery. The US Marshals Service then took up the case and still works to prove whether the men are still alive.