The US nuclear submarine SCORPION (SSN 589) was lost on 22 May 1968 because the explosion at 18:20:44 Greenwich Mean Time (GMT) of hydrogen out-gassed by the TLX-53-A main battery created over-pressures that were more than several times the 100-percent fatal level in spaces forward of the reactor compartment and at lower, survivable levels in spaces aft of the reactor compartment. SCORPION was at periscope depth when the battery explosion - which did not breach the pressure-hull - occurred. At least one member of the crew successfully exited SCORPION through the after escape trunk.
 
Over the following 21m, 50s, SCORPION sank vertically at an average of 0.66 knots to collapse (implode) at 18:42:34 GMT at a depth of 1530-feet in 37milliseconds (ms), 1/27th of a second, with an energy release equal to the explosion of 13,200 lbs of TNT created by the essentially instantaneous conversion of potential energy (sea pressure of 680 psi) to kinetic energy, the motion of the water-ram which entered the SCORPION pressure-hull with an estimated average velocity of about 2000 mph.

It was this compressive force that “telescoped” after sections of the pressure-hull, moving frame 90 forward to frame 67 (a distance of 56.66 feet) at an average velocity of 1044 mph. The Engineering Spaces telescoped into the Auxiliary Machinery Space (AMS) and Reactor Compartment because of the failed transition joints in the AMS. This action produced an average applied force 643 times normal gravity (643g). The estimated final velocity was 2045mph. The estimated final force was 2500g. This calculation by a consulting engineer is consistent with the conclusion that the still-articulated body sighted in the debris field was neither within the pressure-hull nor the after escape trunk when SCORPION collapsed. Bodies subjected to compressive forces of the magnitude associated with collapse at SCORPION's pressure-hull at a depth of 1530-feet do not remain intact.