VENICE — Packed with 600 tons of ammo and explosives, the USS Serpens died in a flash beneath a full moon at 11:18 p.m. on Jan. 29, 1945.

The blast was so violent it rained shrapnel and debris on the island of Guadalcanal a mile away, killed a soldier onshore, knocked everyone standing within that radius off their feet, and flung one sailor into another vessel moored 650 yards away. That ship, the USS YP 514, had its bow and crow's nest demolished, and counted 14 injuries as "missiles" and "screeching shells" continued to explode and turn night into day.

Witnesses said the calamity generated an 8-foot tidal wave, and that the ground shock rippled five miles out. Some said the sky drizzled oil for up to two hours. When bystanders regained their senses, the 100-ton barge that had been transferring bombs onto the Serpens had vanished, and all that was left of the 441-foot cargo ship was its sinking bow, keel up.

Miraculously, two sailors who had been asleep in a forward hold survived. Few other bodies were recovered intact. When the counting was done, 193 Coast Guard crewmen, who had been manning the Navy ship, were gone — along with 56 Army stevedores and an onboard civilian doctor. It was, in short, the most catastrophic single-event loss of life in the history of the U.S. Coast Guard.

Four years later, in what Arlington National Cemetery describes as "the largest group burial" ever hosted, the remains of the 250 casualties from that disaster were retrieved from Guadalcanal, placed in 52 flag-draped coffins, and laid to rest in 28 graves.

According to the Navy, which conducted the investigation, the Serpens blew up during the accidental mishandling of bombs, torpedoes and depth charges. But the son of a crew member isn't buying it.

After pressing Florida politicians and pursuing government records with Freedom of Information Act requests, Robert Breen of Venice has discovered curious gaps in the Serpens' obituary. And at 76, the retired Central Intelligence Agency senior finance officer and certified fraud investigator wonders if he's onto one of the last coverups of World War II.