MONROVIA (CBSLA.com) — A brush fire ripped across 175 acres of Monrovia’s rolling hills Saturday, fueled by terrain that has not seen a fire in 55 years.

Fire crews have contained 50 percent of the blaze and allowed most of the residents evacuated earlier in the day to return home. Evacuation orders are still in effect for Hidden Valley, Alta Vista, Briar Cliff and Highland.

The blaze, also called the Madison Fire, ignited shortly after 11 a.m. on Crescent Drive and Madison Avenue near the 210 Freeway.

Authorities believe it was accidentally sparked by a gardener’s power tools.

“We’re very comfortable right now with the situation, the fire is lying down. We don’t anticipate any wind tonight. The weather report for the night is humidity will be very high and no winds, so we’re very optimistic in that respect. Certainly, we’re going to keep resources on scene through the night and into tomorrow just in the event of spot fires picking up,” Monrovia Fire Chief Chris Donovan said.

Multiple fire agencies are assisting in the firefight, including Monrovia, Arcadia, Pasadena, San Marino, and Los Angeles County Fire.

The U.S. Forest Service and Los Angeles City Fire have been called in to assist, along with seven water-dropping aircrafts. A total of 65 fire engines were working the fire.

One firefighter suffered a heat-related injury. No other injuries were reported.

No structures have been damaged.

When the fire reached its peak during the afternoon, authorities decided to evacuate eight residential streets as a precautionary measure. By 6 p.m., authorities had cleared out 17 streets. Many of those orders had been lifted by 10 p.m.

“We were told to evacuate, it wasn’t mandatory at that time, we had a fire coming our way. Within 20 minutes or so, that fire was blazing, coming over our mountain. I live on Highland Place. Right on Highland Place, the entire backyard area of the entire street is gone,” Monrovia resident David Fernandez said.

Members of the Red Cross are attending to residents at an evacuation center that has been set up at Monrovia Community Center, located at 119 W. Palm.

Click here for a list of evacuated areas. Stay with cbsla.com for more details as they develop.