UC Davis fire investigators say a spark from a lawn mower ignited tinder dry grasses near the Putah Creek Cold Water Facility, causing a fire that threatened some research projects.

The three-alarm fire on Sept. 18 blackened about 20 acres of land that supports fish research for the Center for Aquatic Biology and Aquaculture. Smoke could be seen for miles southwest of the campus near Road 98.

“We quickly upgraded our response to three-alarms because research facilities were in the pathway of the fast-moving fire,” said Phil Davis, assistant chief with the UC Davis Fire Department and incident commander of the two-hour firefight. “All county resources responded to the mid-afternoon fire along with units from Dixon and Winters.

“Once the low-burning grass fire hit the heavy brush and tree grove, the fire exploded in the trees causing 30-foot flames.”

More than 30 firefighters from six agencies responded. No injuries were reported, and no structures were burned. The only damage was to above-ground water pipes that were crushed by fire engines, moving from one section to another, Davis said.