A fire that broke out Monday in the Santa Ana River bottom between Jurupa Valley and Riverside blackened nearly 40 acres and threatened homes before crews slowed it down, then turned their attention to a second blaze that branched off from the main one amid windy conditions.
The main blaze started about 11:10 a.m. in the area of Jurupa Avenue and Van Buren Boulevard, less than a mile north of Riverside Municipal Airport, according to the Riverside County Fire Department.
As of 4 p.m., crews had partially contained the fire, but a separate blaze sprang up ahead of the larger fire, beginning as a small spot fire that quickly expanded to five acres near the Western Riverside County Animal Shelter.
Multiple engine, truck and hand crews from the county, city of Riverside, Corona and Murrieta Fire & Rescue were working to encircle the main blaze as it moved east in thick vegetation. The smaller fire was a couple hundred yards away.
At 12:40 p.m., the main blaze turned north, immediately threatening properties near Kennedy Street and Riverdale Place in Jurupa Valley. A mandatory evacuation was ordered in the neighborhood, but at 1:50 p.m., the order was downgraded to an evacuation warning.
Two Cal Fire water-dropping helicopters made a series of runs that slowed the main fire’s progress, allowing crews to form protective lines around the homes.
A battalion chief at the scene described the winds as “erratic,” hampering containment efforts.
Two additional helicopters were called in to make drops on the new blaze, near the animal shelter.
The cause of the main fire was not immediately known.
The river bottom is dotted with homeless encampments, and during dry periods, fires from camping and cooking are a regular occurrence.