Firemen and other emergency workers sent the 15 students, including four girls, to three hospitals for treatment. Most of the students suffered lacerations to the face, chest and knee. Several of them had to have stitches to close the wounds. According to police, a city bus owned by Sanchung Bus Co. was carrying more than 30 students from Banciao city to their school, Taishan Senior High School in Taishan township, when the accident occurred.

Kung Chun-min, the 38-year-old bus driver, said that as he drove onto the Dahan Bridge, he found that the roadway was covered with a film of grease.

"I was driving at 40 kilometers per hour when I noticed that the truck ahead of me had stopped. I started to brake from 100 meters away, but still could not stop the bus," he said. Chiu Ching-han, 33, the driver of the combination truck, said he also noticed the film of grease on the bridge and had stopped the truck in order to caution traffic policemen on the other side of the road about the potential hazard.

"The accident would not have occurred if I had minded my own business," he said.

Police said the grease on the bridge was probably the main cause of the accident, but they could not be certain whether it had been left by a construction team or was the result of a previous vehicular accident.