One person died and about 60 people were displaced in a fire at a residential building in Baldwin Park on Sunday night, KTLA reported.

What is known

Los Angeles County firefighters were called a little after 8 p.m. to the 12800 block of East Ramona Boulevard, in the San Gabriel Valley. NBC Los Angeles reported that the department raised the incident to a second alarm at 8:25 p.m. and that crews were working in what the department described as offensive mode, meaning they were inside the structure rather than fighting it from outside. The fire was later raised to a third alarm.

Crews removed one person from the building. NBC's account, published while the fire was still burning, did not confirm a death; the fatality was reported afterward as the incident escalated.

The number displaced is given as approximately 60.

What is not known

The cause has not been released. The Herald has seen no indication from the county fire department of any determination about how the fire started, and readers should treat any early explanation with caution.

The person who died has not been publicly identified, and there is no confirmed count of injuries beyond that death. Arrangements for the displaced residents, including whether the American Red Cross has opened a shelter, had not been detailed in the accounts available overnight.

Why the alarm level matters

Alarm levels are a measure of resources committed rather than a direct measure of damage, but they track the seriousness of a fire in real time. A second alarm brings a substantial additional complement of engines and personnel; a third brings more again. A residential fire that reaches a third alarm in a dense part of the San Gabriel Valley is a significant incident, and the displacement figure reflects that.

Baldwin Park is a city of roughly 70,000 people in the eastern San Gabriel Valley, with a housing stock that includes a considerable number of older multifamily buildings. Displacing 60 residents in a single night is a serious problem in a part of the county where affordable vacancies are scarce.

This story will change

This is an overnight account of a developing incident, assembled from local reporting while crews were still on scene. Casualty figures, the number displaced and the cause are all subject to revision by the county fire department. The Herald will update the story as officials release more.