The Squalus was diesel-electric submarine that was commission on March 1, 1939. It was a 310 feet and displaced 2,350 tons when submerged. Just a few weeks after it was commissioned the Squalus would capture the attention of nearly every American, causing newspapers to run extra editions to provide updates. On March 23, 1939, the Squalus sank off the coast of New Hampshire. It was the Sculpin who saw the marker buoy and was able to make contact in order to confirm there were survivors on board, however they were already suffering from the chlorine gas that was leaking from the battery compartment.
The Squalus had 56 sailors and three civilians on board when it dived on March 23. The air induction valve failed and water poured into the aft engine room. The submarine sank down 240 feet to the bottom. The aft section flooded and killed 24 sailors and 2 civilians. In the forward compartment 32 crew members and one civilian sent up the marker buoy and red smoke bombs to alert those on the surface of their plight.
The communication did not last long as the cable parted. The Sculpin stayed by its sister sub and the following morning the USS Falcon arrived. The rescue ship lowered the Momsen-McCann rescue chamber immediately. The chamber was little more than a modified diving bell manned by deep-sea divers but it managed to reach the Squalus and the crew. In three agonizingly slow trips 26 men were brought to the surface.
With seven men still trapped the cables of the rescue chamber became tangled and delayed dive. But in the pitch-black hours just before midnight a fourth trip rescued the final seven men after 39 hours of being trapped. In one more desperate dive the aft compartment was searched to verify that there were no survivors. Several weeks later a massive effort brought the Squalus to the surface and then it was towed to Portsmouth. There an investigation was conducted on the engine room compartments and the submarine was decommissioned on November 15, 1939.