Update: Containment of Border 6 Fire in San Diego County grows to 50%

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Updated: 6:44 a.m. June 4

First discovered: 3 days ago, 1:54 p.m. June 1

Initial location: Tijuana River, Marron Valley, San Diego County, Calif.

Fire unit: Cal Fire San Diego Unit

Fire type: Wildfire

Fire name: Border 6 Fire

Border 6 Fire initially started 1:54 p.m. June 1 in Tijuana River, Marron Valley in San Diego County, California.

Since its discovery three days ago, it has burned 2,617 acres. As of Thursday morning, a fire crew of 130 effectively contained 50% of the fire. The cause of it is still under investigation.

Firefighting efforts include 10 engines, four water tenders, four helicopters and four hand crews. According to Cal Fire, "Numerous firefighting air tankers from throughout the State are flying fire suppression missions as conditions allow."

See live video from the area:

Https://cameras.alertcalifornia.org/?id=Axis-Otay2

Fire containment

What does 50% containment mean?

Containment indicates what percentage of the fire perimeter has been surrounded by a control line. In this case, it means that 50% of the wildfire is halted from spreading, while 50% 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

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This story was originally published June 4, 2026 at 7:17 AM.