HOUSTON (AP) -- A school bus plunged off a highway overpass in Houston after being hit by a car on Tuesday, killing two students and seriously injuring three other people, police and school officials said.
A 17-year-old female student died at the scene, while a 14-year-old girl died at a hospital, according to the Houston Independent School District. The driver and the other passengers on the bus -- two male students -- are hospitalized.
The names of the students haven't been released.
Police spokesman Victor Senties said investigators believe that a car struck the front driver's side of the bus after swerving to avoid another vehicle during morning rush-hour traffic. The bus lurched to the right, struck a guardrail and toppled to the road below, Senties said.
Senties said it's too early to determine if any charge will be filed.
Photos and video of the accident show debris scattered around the yellow bus, its front end heavily damaged and its roof caved in.
School officials said the bus was near the end of its route, so it didn't have many students on board.
Investigators are trying to determine if cameras along the highway or nearby could reveal how the accident happened, Senties said. Footage from the bus' seven security cameras also is being reviewed.
The bus was purchased new in 2008, and was equipped with lap belts. It wasn't immediately clear if students were wearing the lap belts. Nathan Graf, the district's general manager for transportation, said it's optional for students to wear the belts because enforcing their use is too difficult for drivers.
Houston operates the largest public school district in Texas with about 215,000 students. The district has about 950 buses on the road each day, transporting 34,000 students.