A Colorado Springs fire engine collided with a passenger bus Saturday, sending nine people to the hospital and shutting down Tejon and Bijou streets for several hours.

Four firefighters and five Bustang passengers were injured in the crash, which occurred around 10 a.m. while the fire engine was responding to a possible overdose call with its lights and sirens blaring, Fire Department spokesperson Ashley Franco said.

The extent of the injuries and the cause of the crash were unknown.

The doors to the bus were pinned, so firefighters had to pry them open to get people off the bus. The fire engine was pushed into a parked vehicle, which also sustained damage.

The crash totaled the fire engine, so firefighters will have to use a “significantly older” reserve engine while the Fire Department replaces the wrecked vehicle, Franco said.

While she didn’t have an exact number, Franco said crashes involving fire engines happen more than people think.

“So, we really ask people to pay attention to lights and sirens if we’re responding to a call. Obviously, we don’t know what happened here today, but that’s something to always keep in mind,” Franco said.

The Police Department’s crash unit is investigating the collision. Preliminary findings from police indicate that the front passenger side of the bus struck the fire engine, but which vehicle struck which first does not indicate who was at fault, Police Department spokesperson Ira Cronin said.