An early-morning fire that burned through an East Bay construction site has been contained, but not before spreading to some residences and displacing an unknown number of people.

According to officials with the Alameda County Fire Department, calls reporting flames at a construction site on the 3800 block of San Pablo Avenue in Emeryville began pouring in at 2:45 Thursday morning.

The blaze quickly escalated to six alarms, fire officials say, as crews used a drone from the Alameda County Sheriff's Office to identify hot spots from above.

Officials with the East Bay Municipal Utility District also upped the water pressure at the site in an effort to help crews extinguish the flames. According to CBS 5, over 25 units from area fire departments were on site to battle the blaze, which area residents say was visible from I-880, I-580, Highway 24, and the Bay Bridge.

By 7:50 a.m., Alameda County fire officials say, the fire had been controlled. The building under construction, which the Chron reports is "The Intersection," a 105-unit apartment complex (here's its website), was a "total loss", the ACFD says via Twitter.

The fire had also spread to some adjacent townhouses and condominiums in the area, which is near the confluence of West MacArthur, 40th, San Pablo, and Adeline Streets — the site of a significant amount of new development in the past decade. Preliminary reports say that all the residents were safely evacuated, and no injuries were reported. The people displaced by the blaze, the number of which is as yet unknown, are currently receiving assistance from the Red Cross at the Emeryville Senior Center.

“The main body of fire produced so much heat it ignited some of the [neighboring] townhomes,” Battalion Chief Jim Call of the Alameda County Fire Department told the Chron.

“It’s just difficult fire to get to because it’s in so many void spaces.”

According to KRON 4, a security guard said that he heard fireworks go off moments before the fire erupted. The cause of the blaze, officials say, remains under investigation.