The fire sparked near Ventura Avenue around 9 a.m. on Thursday
Fire crews believe the grass fire was started by an arsonist, and say the suspect is still in the area. It wasn't immediately clear if a person was in custody.
Multiple Fresno Fire units are working a vegetation fire along the 99 near Ventura, possible arson fire, suspect still in the area. Use caution driving near the incident. pic.twitter.com/e081Mqxigy
— Fresno Fire PIO (@FresnoFire) June 11, 2020
The California Highway Patrol closed the Ventura on-ramp to drivers as firefighters dealt with the flames.
This is a developing story. Stay with Action News for updates.