Large fire burns a vacant Downtown Fresno building

FRESNO, Calif. (KFSN) -- Firefighters said crews have knocked down the bulk of the fire and structural engineers will soon go in to assess the building to determine whether it's safe enough to reopen Ventura Street to traffic.

Officials said the flames were so intense and burning so hot it caused the roof to collapse on the nearly 20-thousand square foot building. It took about 20 pieces of equipment and 75 firefighters to get a handle on the blaze, and because of the large scale response, the department had to cease emergency responses and call American Ambulance for backup.

Nearby power lines were also a concern. At one point, firefighters knocked out power to about a hundred nearby businesses. Power has since been restored to the north side of Ventura Street, but a handful of businesses to the south are still without electricity.

Fire Chief Kerri Donis said it was her who spotted the flames on her way to work and called it in to Fresno Fire. She said she is particularly concerned with so many fires breaking out in Downtown Fresno in recent weeks. "That's becoming a growing concern and they've been quite large fires so our resources are taxed. So we'll keep our eye on that."

Donis said the fire appeared to have started in the front portion of the building and was centrally located, but said fire investigators are going to have to determine the cause.

As of late Thursday morning, a portion of Ventura Street -- from Broadway to G Street -- was closed until engineers deem the building safe. Fire crews will remain here throughout the day keeping an eye on any hotspots that may flare up.