LOS ANGELES - At least two people were killed and nine were critically injured on Thursday when a bus collided with a tour vehicle on a bridge in the US West Coast city of Seattle, officials said.

Some of those on board the “"Ride the Ducks” vehicle - amphibious vehicles used for tours in several US cities - could be seen crawling out of the wreckage. Fire officials said at least 50 people were evacuated from the site.It was not immediately clear what caused the crash.