Peruvian sailors broke the Pacific's surface "gasping and screaming from pain" after a rapid 110-foot ascent from their sunken submarine, which was running out of fresh air, a navy officer said.

The Peruvian navy said Tuesday that one of the sailors died of the bends on Monday but that the others were recovering.The navy originally said 21 sailors were saved Saturday with a U.S.-supplied diving bell that brought them slowly to the surface.

But the officer, who participated in the rescue operation, said Tuesday that the diving bell did not arrive in time for the trapped crewmen, who "would surely have died" if they did not use a dangerous escape chamber similar to a torpedo tube.

The officer, speaking on condition of anonymity, said that after their escape the men, suffering from severe cases of the bends, were rushed in speedboats to decompression chambers on shore.

Four other sailors were killed shortly after the Japanese fishing boat Kyowa Maru rammed the submarine Pacocha on Friday three miles off the Callao harbor, causing the vessel to sink in 15 minutes.

The navy said 45 sailors of the 52 aboard either were rescued or survived by jumping into the water as the submarine went down.

Three sailors are still missing and presumed dead.

The submarine's commander, Daniel Nieve, and three crewmen were killed shortly after the crash. The navy said Nieve led the evacuation but died sealing a hatch to protect the men inside.

The navy officer who spoke with The Associated Press gave this account:

Rescuers reached the site at 8 p.m. and divers swam to the crippled Pacocha shortly after midnight. The vessel was half full of water and divers did not think anyone was alive.

Divers tapped in code on the crippled submarine's hull, which drew a response and the trapped crewmen began communicating with divers via a message hatch on the craft's side.

"They said they had food and air and everyone was calm," the officer said.

At 8 a.m. Saturday navy officials decided to await help from the United States, and a specially designed diving bell was due late that night. But air supplies dwindled faster than expected.