A small brush fire sparked near National City Thursday evening, just minutes after a countywide red flag warning expired.
The blaze began around 5:15 p.m. off Interstate 805, near the 1400 block of South 45th Street.
San Diego Fire-Rescue officials said it burned about one acre off the side of the freeway. Black smoke could be seen for miles, as reported by residents and commuters in the area. It wafted into downtown San Diego.
Crews have responded to fires in that area before, so they knew dry bamboo there would add fuel to the fire.
Officials placed firefighters at 45th and 43rd streets to pinch the fire off on both sides. Embers did cause a flare-up on the other side of the freeway, but crews doused it quickly.
No structures were threatened.
However, the fire did impact the freeway.
Officials shut down the right lane of southbound I-805 at 43rd and 47th streets in National City. The Palm Avenue exit was also closed, so traffic was backed up to Sorrento Valley as a result.
San Diego had been under a red flag warning through 5 p.m. as firefighters continued to battle several wildfires that destroyed homes and forced evacuations across the county.
Get complete coverage of San Diego's May Firestorm here.