A forensic police investigation has determined that a gas leak caused the tragic bus fire that killed 20 students and three teachers on Tuesday. Pol Lt Gen Trairong Phiewphan, commander of the Office of Police Forensic Science (OPFS), confirmed on Thursday that the leak occurred at the front of the bus, though the source of the spark that ignited the fire and the reason for the gas leak remain under investigation.
Specialists in vehicle gas systems will be brought in to assist in further inquiries. The investigation also revealed that the bus was equipped with 11 compressed natural gas (CNG) tanks, only six of which were legally registered. The leak originated from one of the unregistered tanks, which had not undergone a safety inspection.
A House committee on transport has summoned officials from the Department of Land Transport (DLT) and the Automotive Engineering Bureau (AEB) to clarify the cause of the fire and propose preventive measures. Chirute Visalachitra, the DLT’s director-general, reported that the police and department are collaborating to identify the party responsible for the oversight in allowing the unregistered tanks.
The inspection debunked earlier reports of a front tyre explosion but did confirm that the bus’s front-wheel shaft had broken and scraped along the road. The fuel line carrying gas from the tank to the engine had detached, leading to the gas leak. Initial reports suggested that the fire began after the driver, Samarn Chanphut, 48, lost control when the front left tyre blew out, causing the bus to crash into a median and quickly ignite.
Following the accident, the DLT suspended the operating licence of Panisara Chinnaboot, the owner of Sing Buri-based Chinnaboot Tour, with the possibility of revocation if negligence is proven. Additionally, Kanittha Chinnaboot, the company’s transport safety manager, had her registration revoked. An investigation into Alternative Resource Engineering Co, responsible for inspecting gas-fuelled vehicles, is also underway.
Authorities have suspended the bus driver’s licence and will review all 13,426 vehicles using CNG within 60 days.
