Taiwanese officials investigate cause of deadly train crash

April 3 (UPI) -- A construction site manager suspected of negligence related to this week's train crash in Taiwan appeared in court Saturday, according to media reports.

Officials say a maintenance truck slid onto the railroad track, hitting a passenger train which then crashed inside a tunnel Friday.

The construction site boss, who was not in the vehicle at the time of the accident, has reportedly been released on bail.

The Taiwan Transport Safety Board is investigating the accident and trying to determine whether the truck's brakes were properly applied or whether there was a mechanical failure, the South China Morning Post reported.

The train was traveling from New Taipei City to Taitung and was carrying 490 passengers.

As of Saturday at least 51 passengers were killed in the collision and nearly 180 were injured, making the incident Taiwan's worst disaster in 70 years -- and rescuers are worried they may find more bodies as they continue to extract carriages from the tunnel.

The crash occurred on the first day of the Qingming Festival, also known as Tomb-Sweeping Day, which often draws large numbers of visitors.