There's an emergency air system that the fire fighters can plug into. However, the fire comprised the system and the FFs plugged in to a fatal supply of toxic gases.
Abandoning the sub, some of the officers were still inside when it went down. They made their way to an escape pod, but by the time they sealed the hatch, they also sealed in a multiple of atmosphere.
When the pod hit the surface, the hatch blew, killing one guy that went out with the excess air pressure, while another was thrown half way out. He was able to escape the escape pod before it filled with water, taking the remaining occupants down.
At the time, the Soviets stationed a vessel above it, cognizant of the Glomar Explorer...
Nice post...thanks