NORCO (CBSLA) – A 175-acre brush fire which broke out in the Santa Ana Riverbottom in Norco Tuesday morning has forced major evacuations.

The Mann Fire was reported at around 9:50 a.m. near the area of California Avenue and Grulla Court.

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(credit: CBS)

By 11:30 a.m., the fire had grown to 100 acres with no containment, according to the CAL Fire Riverside Fire Department.

Mandatory evacuations were issued for homes north of North Drive, between Crestview Drive and California Avenue, north of 8th Street, east of Pedley Avenue and south of the Santa Ana riverbed.

“I went to the other ranch where I have three other miniature horses and I saved them,” said rescuer Lori Evelyn.

Approximately 500 homes were threatened and about 1,500 people were said to live in the area.

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“You’re looking at about 1,500 residents that were affected by this fire, approximately 500 homes,” said Riverside County Fire Department Capt. Fernando Herrera. “A lot of those folks were put on ordered evacuations.”

210 firefighters were battling the blaze on the ground and in the air. Several neighboring agencies, including the Los Angeles County Fire Department were assisting in the firefight. Three water-dropping helicopters were assigned to the blaze.

Evacuation centers were set up at both Corona and Jurupa Valley high schools. Large animals could be taken to George Ingalls Park.

By 5 p.m., the fire was 20 percent contained and firefighters were able to stop the forward progression of the flames.

There was no word on what may have caused the fire, but according to firefighters, the origin was located where homeless people are known to camp.

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No structures were lost in the fire.