Thai police said the crane, operated as part of a high-speed rail project in Sikhio district of Nakhon Ratchasima province, about 230 kilometers northeast of Bangkok, collapsed and struck one of the train's carriages while it was in motion.
Authorities said the train was carrying 195 passengers and crew members. Of the 64 injured, seven are in critical condition. A fire that broke out after the derailment was extinguished, and search and rescue operations are ongoing.
Transport Minister Piphat Ratchakitprakan ordered an investigation to determine the cause of the accident. Prime Minister Anutin Charnvirakul said such incidents happen "far too often" and called for changes to the law to blacklist construction companies repeatedly linked to fatal accidents.
Most of the injured have been hospitalized, and an emergency center was set up at the scene to assist passengers with alternative travel arrangements. Officials warned the death toll could rise.
