DEHESA (CNS) - A wildfire spread over an open, hilly area near Sycuan Casino Tuesday, blackening about 25 acres but posing no structural threats.

The slow-moving blaze erupted near the intersection of Dehesa and Sloane Canyon roads about 9:30 a.m., according to Cal Fire.

Crews on the ground and aboard air tankers and water-dropping helicopters worked to subdue the flames, said Jon Heggie, a fire captain with the state agency. The personnel had the spread of the blaze halted within about 90 minutes.

By late afternoon, firefighters had the smoldering burn area about 95 percent contained.

One crew member was transported to a hospital for evaluation of a bee sting suffered while working to extinguish the blaze.

The cause of the fire was under investigation, Heggie said.

This is a developing story. Check back for updates.