Different news sources give varying numbers of lives lost.
BBC» state 34 known fatalities, and that this may rise.
Some reports state that the train struck a "dislodged" maintenance vehicle, others suggest maintenance equipment.
The impact was in a tunnel, but only part of the train is within the tunnel with the rest in the open.
Taiwan railways have a generally good safety record.
https://www.bbc.co.uk/news/world-asia-56612248 Link includes pictures of the scene, which I appreciate some may consider inapropiate, but already on a publicly viewable and reputable news site.
The bereaved and injured are no doubt in our thoughts.