SAN LEANDRO -- About 75 people at a San Leandro apartment building were temporarily displaced and huddled for warmth in nearby San Leandro High School's cafeteria Thursday morning after a fire broke out in a first-floor unit.

The blaze began about 4:39 a.m. at Chateau Bleu -- a three-story, 100-unit complex at 2199 Bancroft Ave., and a second alarm was sounded, but no one was seriously injured, Alameda County Fire spokeswoman Aisha Knowles said. Crews at the scene gained control of the fire by 5:30 a.m., and the second alarm was canceled.

Gerardo Prado, who lives in a first-floor unit with his wife and two children, ages 3 and 9, said his family awakened to the sound of his brother pounding on the front door. Prado's brother lives in the unit above him, he said.

Alameda County firefighters assess the situation in the aftermath of an early morning apartment fire in the 2100 block of Bancroft Avenue in San Leandro,
Alameda County firefighters assess the situation in the aftermath of an early morning apartment fire in the 2100 block of Bancroft Avenue in San Leandro, Calif., Thursday, Dec. 5, 2013. (D. Ross Cameron/Bay Area News Group)

"He yelled, 'There's a fire; there's a fire,'" he said. "I grabbed my kids, wrapped them in blankets and ran out. There was no fire alarm going off. I don't know what would've happened if my brother hadn't come down."

Crews arrived to find some residents already huddled together outside, trying to stay warm in the 35-degree weather. School officials were contacted and opened up the cafeteria at the high school for those who had to evacuate, Knowles said.

All four people residents of the unit where the fire started escaped, Battalion Chief Ronnie Oatis said. A smoke detector in the apartment sounded, waking up the four, and they all were outside by the time crews arrived, Oatis said. The Red Cross was working with them to find housing.

An adjacent downstairs unit also was uninhabitable, though it was not known immediately how many people lived there. Oatis said the complex was equipped with a manual fire detection system, but that nobody activated it.

Two residents in the apartment were treated for injuries at the scene, Knowles said. One complained of chest pain, while the other was having difficulty breathing, she said.

Most of the residents who evacuated and spent the chilly morning congregated inside the high school were cleared to return to their units at 7:45 a.m., Knowles said.

Later that morning, San Leandro High School started classes on time, officials said.

Earlier Thursday, San Leandro fire crews responded to another fire.

About 12:40 a.m., a dumpster caught fire outside the Subway at 14972 East 14th St., off 150th Avenue.

The dumpster was up against the business, and flames from it spread up Subway's outer wall, Oatis said.

Crews had the fire out within minutes, and the business did not sustain major damage.

No one was injured, Knowles said.

The cause of that fire remained under investigation on Thursday.

Contact Rick Hurd at 925-945-4789, and follow him at Twitter.com/3rderh.