The crash occurred last month when a Caltrain carrying about 75 passengers hit three maintenance vehicles.
Maintenance vehicles hit by a Caltrain in San Bruno last month received authorization to be on the tracks 43 minutes before the crash, but then released that approval eight minutes later, according to a preliminary National Transportation Safety Board report released Wednesday.
The federal agency, which conducts independent investigations into significant transportation collisions, is investigating the circumstances around why a Caltrain struck its own agency’s on-track maintenance vehicles. The report does not address why the three maintenance vehicles were still on the track when the Caltrain struck them about a half an hour later.
On Mar. 10, southbound Caltrain train #506, which was carrying about 75 passengers, hit three stationary high-rail maintenance vehicles at about 10:33 a.m. near a milepost on the second track, according to the NTSB report. The train was derailed, destroying all three maintenance vehicles. Fuel from the vehicles also fueled a fire that spread to a passenger rail car. Fourteen people were injured, including 12 passengers, one train crew member and a maintenance contractors. Seven were hospitalized while the other seven were treated at the scene.
Trains were held on both tracks after the crash. Service was disrupted until further notice as crews work on making repairs. Property damage is estimated to be nearly $1.4 million, the report said.
The agency hasn’t listed an official cause of the collision.
According to the investigation, the roadway worker in charge got exclusive track occupancy, meaning trains and other equipment are permitted to be on the track, and the maintenance vehicles entered track two at about 9:50 a.m. They stopped to load catenary poles and construction materials from a fenced-in location next to the main track. Eight minutes later, the worker contacted the train dispatcher to release track occupancy.
The train was traveling on track two about 63 miles per hour towards Millbrae Station, after stopping at the 22nd Street Station, the report said. Track two has a maximum allowed speed of 79 miles per hour. The engineer tried to stop the train as it approached the milepost and the three vehicles on the track, but the train didn’t make a complete stop before hitting the vehicles. Crews started evacuating passengers through the railcars near the back of the train.
Employees of the San Bruno Water Corporation Yard used work equipment at the scene. First responders also arrived at the scene. Passengers and crew were evacuated and the fire was under control by 11:14 a.m.
The NTSB investigators examined the track, location of the collision, equipment and the signal system and conducted interviewed. They also tested the train’s brake system and gathered records from employees and systems. The investigation is ongoing and will focus on railroad worker safety, regulatory compliance and training and oversight.
Caltrain didn’t respond to requests for comment Wednesday but previously said it didn’t have any information on why the equipment was on the tracks during the collision.
“Obviously, the truck shouldn’t have been there,” Caltrain spokesperson Jeremy Lipps said. “Why it was there — we don’t know.”
