WASHINGTON (AP) _ A second crew member or the requirement of an alarm system in towboat wheelhouses might have prevented the deadly 2002 Interstate 40 bridge collapse, federal transportation investigators said Tuesday.
An alert system notifying motorists of the fallen bridge might also have reduced fatalities in the May 26, 2002, collapse of the Arkansas River bridge in Oklahoma, the National Transportation Safety Board said.
The NTSB approved the findings, probable cause and safety recommendations from its investigation into the accident, which killed 14 people whose vehicles plunged into the river near Webbers Falls, Okla.
Five more motorists were injured when two barges pushed by the Robert Y. Love rammed the bridge's piers, knocking about 500 feet of the span into the water. It caused $30.1 million in damage.
The NTSB reiterated the widely reported probably cause: that towboat captain William Joe Dedmon became unconscious before colliding with the bridge because of an abnormal heart rhythm.
The NTSB said Dedmon's heart problem would likely not have been detected in normal physical examinations. It said Dedmon, who was 60 at the time, had not previously passed out from the condition.
Three other crew members were aboard the boat when Dedmon fell unconscious, and had they been alerted to his incapacity, they might have been able to prevent the collision, the NTSB said.
Or, another crew member in the wheelhouse could have taken the necessary evasive action after Dedmon fell ill, the NTSB said.
The investigation concluded that drivers approaching the bridge did not have enough stopping distance after seeing the damage to avoid plunging off the fallen bridge.
Therefore, a motorist alert system warning drivers of the pending damage could have reduced the fatalities, the NTSB said. NTSB staff recommended that the Federal Highway Administration work to improve such systems already in place in Florida and Texas on bridges previously felled by boat accidents.
The board also said that Dedmon was fatigued at the time of the crash, having slept only about nine hours in the two days before the accident, and had taken an over-the-counter allergy medication known to cause drowsiness.
However, the NTSB concluded that neither likely contributed to Dedmon's losing consciousness. He had 40 years experience as a mariner.
Further, Dedmon also had a completely blocked coronary artery, but it had no effect on his heartbeat, NTSB Dr. Mitch Garber said.
Garber said Dedmon's heart condition had not caused him to lose consciousness before, but in interviews after the accident, he reported having felt dizzy and nauseous on another vessel four days prior.