Salvage teams began removing pulverized train carriages on Saturday after Taiwan's worst rail disaster in decades plunged the island into mourning.
At least 50 people have died following Friday's crash near the eastern coastal city of Hualien. With rescuers anticipating the discovery of more bodies inside the wreckage, officials have suggested the death toll may still rise.
By Saturday morning, flags were seen flying at half-mast across Taiwan and they were set to stay that way for the next three days.
Errant truck causes fatal crash
The train was packed at the start of a long holiday weekend — with 492 passengers and four crew on board.
Just moments before the collision, which occurred at around 9:30 a.m. local time (0030 GMT), a parked railway maintenance vehicle slipped down an embankment and onto the track, according to the Taiwan Railways Administration (TRA).
As it approached a narrow tunnel, the train hit the errant truck that lay in its path, derailing many of the carriages as the devastation unfolded.
Some railway experts have suggested the narrowness of the tunnel made the crash even worse, and rescue efforts more difficult.
Prosecutors seek arrest warrant
Prosecutors said they are seeking an arrest warrant for the construction site manager who may have failed to secure the parking break, state-run Central News Agency reported on Saturday.
Investigators began questioning the man late on Friday but had to stop their interrogation when he became too emotional, the agency reported.
For the time being, he has been released on bail and is barred from leaving Taiwan, pending further investigation.