Investigators searched Saturday for clues as to why a chartered ferry capsized in choppy seas, killing at least 19 American sailors who were in the Middle East as part of Operation Desert Shield.

Survivors said the Israeli ferry, called the Tuvia, went under almost instantly after it was swamped early Saturday while ferrying about 100 crewmen back to the aircraft carrier USS Saratoga from shore leave in Haifa."All of a sudden I saw water just come flying in. It was maybe two seconds and the boat rolled right over," said Chief Petty Officer Lance Vickery, 33, of Jacksonville, Fla.

Israeli divers retrieved six bodies from the sunken craft in 65 feet of water. The others were found dead on the surface or died of injuries after being rescued alive, officials said. Three dozen sailors were taken to hospitals, but most were released.

By Saturday afternoon, two men were still reported unaccounted for, but Navy officials said they believed they would be located as crewmen reported back to their ships.

The Saratoga and its three escort ships were in the Red Sea as part of the naval buildup in the Persian Gulf region in the wake of Iraq's Aug. 2 invasion of Kuwait.

The accident was the deadliest involving U.S servicemen in Operation Desert Shield, and it raised the number of Americans who have died to at least 73.

Haifa is a frequent port of call for American sailors. Last year, more than 45,000 sailors attached to the 6th Fleet visited the northern port city.

Several sailors rescued from the Tuvia said the craft may have been overloaded. One of the two Israeli crewmen, Yossi Shochat, said he believed too many sailors were crowded into the boat's stern.But Gen. Micha Ram, the commander of Israel's navy, said on Israel radio that the Tuvia had been licensed to carry 130 passengers but took only about 100 because the seas were running high.

"Until the boat is retrieved and can be examined . . . we cannot point to any negligence," he said.

He said the craft went down in 15 or 20 seconds and added: "I have never known a vessel to sink so fast."

Survivors told of harrowing moments in the water, clinging to life jackets and debris from the 57-foot-long, double-deck ferry. At least some of the injured were struck by a rescue boat.

Six of the injured remained in Haifa's Rambam Hospital on Saturday night. Matty Ilnach, head duty nurse at Rambam, said all were listed as slightly wounded and could be released Sunday.

Cmdr. Craig Quigley, a U.S. Navy spokesman, said 36 sailors were admitted to Haifa hospitals but that most were released immediately after a checkup.

Col. Ranaan Gissen, the Israeli army's deputy spokesman, said more than 30 others were plucked from the waters unharmed in a rescue operation by U.S. and Israeli forces.

Flares lit the sky over the harbor of the northern city for much of the night, and ambulances rushed victims to three Haifa-area hospitals.

Some sailors rescued from the capsized ferry said they had spent their shore leave having dinner, drinking beer or visiting discotheques.

Israel army radio reported that some of the sailors had been drunk and at least one of the dead victims was handcuffed, apparently after being arrested by U.S. military police for drunkenness.

However, Pentagon spokesman Lt. Commander Alan Dooley said no one aboard was in handcuffs.