A longtime USC professor of electromagnetics drowned off the coast of Ventura County on Wednesday while on a diving expedition.
Willard Van Tuyl Rusch, 58, whom friends described as an expert swimmer and diver, was pronounced dead at 10:10 a.m. at Los Robles Regional Medical Center in Thousand Oaks, where he had been taken by a Coast Guard helicopter after the 8 a.m. incident, officials said.
Coroner's investigators were unsure why Rusch, of Pasadena, ran into trouble while submerged in 35 feet of water at Wycoff Ledge, a spot favored by advanced divers off the southern coast of San Miguel Island.
Investigators had not examined Rusch's equipment for possible failure because the dive boat, Peace, did not return to Ventura Harbor until late Wednesday.
"We're still missing pieces of the puzzle," said Deputy Coroner Craig Stevens.
The coroner's office will enlist the help of a diving expert to determine if a malfunction of Rusch's equipment was responsible for the accident, said Deputy Coroner Mitch Breese, who was at Ventura Harbor when the dive boat returned.
Rusch and 21 other divers were at the island, the northernmost in the Channel Island chain, for a day of pleasure-diving when Rusch signed to his partner that he was in distress, said Coast Guard Petty Officer Scott Wasserman. The partner, Steve Lewis, tried to grab Rusch and pull him to the surface, but lost his grip and watched helplessly as Rusch sank to a depth of 90 feet, Wasserman said.
At 6 feet, 4 inches tall and 220 pounds, Rusch may have been too heavy for his partner to carry, Breese said.