There was an underwater explosion under her port quarter, and three minutes later, she had a 10° list to port. The order was given to abandon ship at 13:07, and — one minute later — the port rail was under water.
A catastrophic event occurred beneath her left side, causing the submarine to tilt 10° to port within three minutes. At 1:07 PM, the crew was told to leave the ship immediately, but just one minute later, the entire port side of the vessel had been submerged in water.