Update: Acorn Fire in San Bernardino County at nearly full containment

The creation of this content included the use of AI based on templates created, reviewed and edited by journalists in the newsroom. Read more on our AI policy here.

Updated: 6:53 p.m. May 8

First discovered: 28 hours ago, 2:52 p.m. May 7

Initial location: Acorn Road and Hwy 138, Pinon Hills, San Bernardino County, Calif.

Fire unit: Cal Fire San Bernardino Unit

Fire type: Wildfire

Fire name: Acorn Fire

Acorn Fire initially started 2:52 p.m. May 7 at Acorn Road and Hwy 138, Pinon Hills in San Bernardino County, California.

Since its discovery 28 hours ago, it has burned 10 acres. By Friday evening, the fire crew effectively contained 95% of the wildfire. However, the cause is still under investigation.

See live video from the area:

Https://cameras.alertcalifornia.org/?id=Axis-Table1

Fire containment

This is what 95% containment means

The percentage indicates how much of the fire perimeter has been surrounded by a control line. In this case, it means that 95% of the wildfire is contained from spreading, while 5% is still uncontrolled.

Containment is part of a larger plan for managing a wildfire. It is normally expressed as a percentage and it refers to how much of the fire perimeter has been surrounded/enclosed by a control line that firefighters create. The containment percentage indicates a certain level of control, but it doesn't always correlate to safety level. Also, it's important to note that containment doesn't mean a fire is out.

How is containment measured?

The incident's central command constantly receives progress reports from firefighters on the ground. As the fireline is constructed, inspected or reinforced, mappers record those details to adjust the containment percentage. The percentage tells the public how much of the fire perimeter is believed to not go beyond the control lines.

Source: Cal Fire

United Robots Sacramento

This story was originally published May 9, 2026 at 12:07 PM.