SILVERADO, Calif. (KABC) -- Mandatory evacuations were ordered for residents near the Silverado Canyon fire in Orange County's Cleveland National Forest, authorities said Friday evening.Residents on the 30500 block of Silverado Canyon Road east to the end of the canyon were ordered out of their homes at 6 p.m., the Orange County Sheriff's Department said.A Red Cross evacuation center was opened at El Modena High School, 3920 E. Spring St. in Orange, for Silverado Canyon residents. The shelter was set to close at 10 p.m.Three firefighters have been treated for minor heat-related injuries. Crews were expected to remain on the scene through the night to get containment up before temperatures soared again Saturday. About 500 firefighters are expected on scene, doubling Friday's efforts.Around 10:15 p.m., parts of Silverado Canyon had lost power because of the fire. Southern California Edison worked with city officials on the problem.The brush fire erupted Friday morning, sending up a plume of smoke that could be seen for miles.The fire was reported around 10:30 a.m. on the 30500 block of Silverado Canyon Road. It was initially estimated at 10 acres, but it quickly grew to 350 acres by 1 p.m. By 7:30 p.m., the fire had burned an estimated 1,600 acres.Orange County fire officials said the blaze was burning in a remote area off of Silverado Canyon Road, south of Corona.Two water-dropping helicopters were immediately brought in to help battle the flames. More helicopters were en route to the scene, officials said."When we get into rugged terrain like this, aircraft is key. We need those planes to drop retardant. We need our helicopters to keep the fire in check so it doesn't grow," said Capt. Steve Concialdi with the Orange County Fire Authority. "There are designated bodies of water that they pull from."The cause of the fire remains under investigation.Small animals were being taken in at the O.C. Animal Care Shelter at 561 The City Drive in Orange. Large animals were being housed at the Orange County Fair Grounds in Costa Mesa. Officials asked that owners of large animals call the fair grounds ahead of time at (714) 708-1588.Road closures include North Main, Indian Truck, Bedford and Maple Springs Road. Silverado Canyon Road is also closed to allow fire crews access to the brush fire. A portion of Silverado Canyon Road from Santiago Canyon Road to 30311 Silverado Canyon Road was open to residents only. Santiago Canyon Road is open.