4 Killed, 12 Critically Injured After Tour Vehicle Collides With Bus on Seattle Bridge

4 Killed, 12 Critically Injured After Tour Vehicle Collides With Bus on Seattle Bridge Numerous injuries were reported after a tour bus collided with another bus on Thursday. (Seattle Fire Department)

Four people were killed and dozens more injured - including 12 critcally - when a tour vehicle collided with a bus on the Aurora Bridge in Seattle on Thursday, authorities said.

A Ride the Ducks tour vehicle hit and ripped out the side of a charter bus carrying students at about 11:15 a.m., officials and witnesses told the Seattle Times

Read: Family of Limo Crash Victim Blasts Tracy Morgan For Not Mentioning Him in Emmys Speech

The total number of injured was not immediately clear, but 50 people were being evaluated for injuries by emergency responders after the accident, officials said.

The charter bus was carrying 45 students and employees from North Seattle College's international program, a spokeswoman said.

"We’ve had a terrible tragedy," Mayor Ed Murray said at a press conference. "The thoughts and prayers of this city go out to everyone ­- the families and those impacted."

Witnesses reportedly said the Ride the Ducks vehicle, which offers land and water tours throughout Seattle, appeared to be trying to move into another lane when it hit a car. It then reportedly hit the bus head-on, witnesses told the Times.

All lanes on the bridge were blocked as police and fire departments responded to the scene. A triage area was set up to treat the injured, the Times wrote. 

Read: Oops! Driver Using Selfie Stick Records the Moment He Crashes into Another Car

The Ride the Ducks tour company has not yet responded to a request for comment.

The amphibious vehicles have previously been involved in collisions as recently as July, when a Ride the Ducks tour reportedly vehicle struck a pedestrian, the Times wrote.

Brian Tracy, the chief executive of Ride the Ducks, told the TImes the vehicles have cameras and mirrors placed all over and that drivers are required to take a safety class once a month.

Watch Below: Driver Austin Dillon Survive One of Most Spectacular Crashes in NASCAR History