UPDATE 3, 9:29 p.m.: A police helicopter is reportedly using an infrared camera to check for hotspots down at South Hills, police said.
Fire fighters revised their original estimate and reported about eight acres of dry brush burned Saturday afternoon, according to the San Gabriel Valley Tribune.
About 100 firefighters worked to extinguish the blaze as it snaked its way from west to east. As crews worked to mop up the remnants of the blaze, they originally said a microwave disk on a communication tower had been damaged, but now said this was not the case.
Officials with Verizon were also on scene to assess possible damage to their equipment.
UPDATE 2, 7:20 p.m.: Fire officials reportedly release two of the three helicopters above the scene, keeping one for contingencies.
UPDATE, 7:10 p.m.: Officials on the scene reported 16 acres burned in the South Hills fire. A microwave disk on or near one of the towers on top of the hill sustained damage, but how much is unknown at this time.
Crews are all beginning to officially mop up the area. As of 7:01 p.m., a small spot fire erupted at South Hills.
PREVIOUSLY: A brush fire erupted at before 5 p.m., according to officials at the California Highway Patrol.
The fire burned about three to four acres, according to the San Gabriel Valley Tribune. The fire was burning uphill from near the Glendora Avenue side of South Hills.
Fire personnel on scene report a microwave dish has sustained damage from the fire, but how extensive is unknown, according to scanner reports.
Scanner reports from officers arriving after the first call indicated multiple ignition spots.
A water tender from Monrovia was also on scene fighting the fire with city crews.
A Sig Alert was issued for the two rights lanes of the Westbound Interstate 210 Freeway at Sunflower. Traffic was backed up to the Interstate 57 Freeway, said Christian Cracraft of the CHP.
As of right now three water-dropping helicopters with Los Angeles County Fire are attacking remaining hot spots.
Officials have not returned calls to Patch. The number of total acres burned is not known at this time. The cause of the fire is also unknown.
This story will continue to be updated as information becomes available.