The driver died and 29 Thai and foreign passengers were injured, two of them seriously, when their tour bus, headed to Bangkok from Chiang Mai, slid off the road and collided with a tree on Tuesday night.
The incident happened on the Phahonyothin Road in Ban Mae Tia in the Thoen district of Lampang province.
The driver, known as Churapat Pramaso, got stuck behind the steering wheel, requiring emergency workers to use hand tools to free him, but he was already deceased.
Most of the passengers were only slightly hurt, but two sustained more serious injuries. All were transported to Thoen and Lampang hospitals for treatment.
Authorities believe that the slippery road conditions, following heavy rain, might have played a part in the bus driver losing control of the vehicle.