A plume of smoke rose above Fallbrook Friday east of military base Camp Pendleton. Cal Fire San Diego responded around 10:10 a.m. to a structure fire that spread to brush near Overland Trail and Mission Road north of state Route 76 and west of Interstate 15. Within 20 minutes, crews had stopped the fire’s spread but one residential structure was destroyed, Cal Fire San Diego said in a post on X. Early mapping estimates said the fire had scorched 5 acres but that was later amended to 3 acres. The cause of the fire was not yet known and it was unclear whether the blaze started in the outbuilding and spread to vegetation or vice versa. .@CALFIRESANDIEGO firefighters are responding to a vegetation fire in the area of Overland Trail and Mission Road in Fallbrook. #MissionFire pic.twitter.com/cTCMmfo072 — CAL FIRE/San Diego County Fire (@CALFIRESANDIEGO) January 10, 2025 It was also unclear whether first responders needed initially to evacuate any residents. The fire sparked amid a red flag warning that has San Diego County’s fire agencies are on high alert. Gusty Santa Ana winds and low humidity create a weather concoction that can quickly spark and spread wildfires. Cal Fire previously said their resources were staffed-up and additional crews were pulled in from across the state to quickly respond to any fires that arise amid the warning. This is a developing story. Details may change as information is released.