[Update, 9:45 a.m., Sunday, April 21: Latest updates on acreage, evacuations, and containment in a new story here.]
[Update, 11:53 p.m.: The fire, which has not grown since the last update, has been 50 percent contained. Nevertheless, four neighborhoods involving about 100 homes remained evacuated: Alta Vista, Briar Cliff, Hidden Valley, and Highland. A city spokesperson said it was a precaution "due to the potential for winds to come down through the mountains."]
[Update, 7:30 p.m.: The blaze has grown to 175 acres and was 10 percent contained, as of 7 p.m. 200 homes have been evacuated.]
Firefighting aircraft were called in to protect homes in northwest Monrovia today, as a brushfire covering an estimated 150 acres sent a huge cloud skyward about a mile-and-a-half from a big crowd at Santa Anita Race Track.
Twenty-five fire trucks, about 125 firefighters, and several helicopters were working to protect homes in the steep San Gabriel Mountain foothills, adjacent to subdivisions and hillside residences in Arcadia and Monrovia, Monrovia Fire Chief Chris Donovan said.
At 2 p.m., Monrovia firefighters began evacuating several neighborhoods. Donovan said winds were light, but said those winds normally shift direction in the afternoons in the foothills and 15 additional engines were being called in for structure protection.
The Los Angeles Fire Department sent a strike team with five engines, 25 firefighters, and a water-dropping helicopter to help the Monrovia Fire Department.
As of 4:30 p.m., the brush fire had grown to "150 acres and was only 10 percent contained," Monrovia city spokeswoman Jennifer McLain told City News Service.
"The growth of the fire from 18 acres to 150 acres has also forced fire officials to order mandatory evacuations from 15 Monrovia streets," McLain said.
Those streets included the Heather Heights, Alta Vista, Melrose, Patricia Way, Hidden Valley, Mesa Circle, Sky Way areas, and all the streets north of Scenic Drive between Briar Cliff and Madison near the Arcadia border, McLain said.
"An evacuation center has been set up at 119 W. Palm Ave.," she added. "So far there have been no reports of injuries or structures burned."
The fire broke out near Hillcrest Boulevard and Madison Avenue at 11:06 a.m., and in 45 minutes it had spread to 10 acres in heavy brush. Winds were reported to be light and not a factor, but it nearly doubled in size in the next hour.
Highly-visible flames and smoke snarled traffic on the nearby Foothills (210) Freeway. Initial reports were that a gardener had accidentally sparked the blaze.
A third-alarm was called as Monrovia firefighters brought in Los Angeles County crews to help battle the flames, on the slopes of the San Gabriel Mountain foothills about two miles northeast of the Santa Anita Race Track.
Traffic on the 210 Freeway was snarled all afternoon, as flames and smoke were clearly visible north of the freeway, about eight miles east of Pasadena.