From King 5:

Seattle’s monorail system is shut down indefinitely after two trains clipped each other on a curve in the tracks Saturday evening in the heart of Seattle.

Perry Cooper with the Seattle Center, which operates the monorail, said the tracks at the curve are too narrow for the trains to pass each other. The blue train was inbound and the red train was outbound. The blue train is supposed to yield to the red, but for some reason did not do so.

The trains are now wedged together so hard, neither can be moved and cranes will have to be brought in to move them.