OITA (Kyodo) Four snapped bolt pieces found in the wake of Friday's gangway collapse at a shipyard in Oita indicate the combined weight of the iron walkway and the workers on it was too much for the ship's hook to handle, local police and labor officials said Saturday.
The four bolts, which held the hook to the ship, all snapped at the same time while the gangway was attached to it, they said.
After confiscating and examining fragments of the four bolts, the police have effectively determined from their cross sections that they all broke due to excess weight rather than corrosion, the officials said.
The police are continuing to investigate the accident at Minaminippon Shipbuilding Co.'s Ozai shipyard as a case of professional negligence resulting in death and injuries. They are also checking the weight capacity of area where the gangway was attached to the hook, which was being held in place on the ship by the four bolts.
Witnesses reported seeing nearly 40 people on the gangway at the time it plunged, killing two people and injuring 24 others.
The gangway itself, which the firm said Friday weighed about 3 tons, turns out to weigh about 6 tons, police said.