A fire that started in a drainage culvert underneath the Riverside (91) Freeway was quickly knocked down Monday, without disrupting traffic on the busy corridor.
The blaze was reported shortly after 1 p.m. Monday on the eastbound side of the freeway near Madison Street, according to the Riverside Fire Department.
The agency said several engine crews were sent to the location and encountered smoke billowing up from the canal, spanning the east- and westbound sides of the freeway.
California Highway Patrol officers left all lanes open as firefighters walked down from the freeway shoulder to reach the canal.
The spot fire was smoldering by the time crews got to it, using hand-held gear to completely extinguish it by 1:40 p.m., according to officials at the scene.
The cause of the fire was under investigation. Transients use the tunnels sometimes for shelter.