Fifteen people were hurt Saturday when a METRO bus collided with a sedan and flipped off a Houston bridge, landing on a highway retaining wall, officials said.

The crash happened shortly after 2:30 p.m. near McGowen Street and State Highway 288, according to the Houston Fire Department.

Authorities said 14 passengers on the bus and the sedan's driver were injured. One woman suffered serious injuries and had to be extricated after being pinned inside the wreckage.

All but one of the victims were transported to local hospitals with injuries ranging from minor to severe.

"This kind of response shows how quickly things can change and how important it is for our crews to remain flexible and prepared for the worst," the fire department said in a social media post.

Investigators are still working to determine what caused the crash.