This is local news, but some of the bus experts here may be interested.
Seattle Transit Blog adds:Bus fire on I-5 creates 10 mile backup
Credit: KING
A Sound Transit bus caught fire in the Interstate 5 express lanes in Seattle, Jan. 11, 2013.
A Sound Transit bus caught fire in the Interstate 5 express lanes in north Seattle Friday, creating a backup of at least 10 miles southbound and another backup northbound.
It looks to be one of the new-ish DE60LFs that have been coming in.