Updated: 8:16 p.m. July 17

First discovered: 37 hours ago, 6:25 a.m. July 16

Initial location: Near Pine Avenue and Corona Freeway, Chino Hills, San Bernardino County, Calif.

Fire unit: Unified Command: Chino Valley Fire District & Cal Fire San Bernardino Unit

Fire type: Wildfire

Fire name: Pine Fire

Pine Fire initially started 6:25 a.m. July 16 at Near Pine Avenue and Corona Freeway, Chino Hills in San Bernardino County, California.

By Friday evening, it had burned 20.5 acres. As of Friday evening, 50% of this wildfire was brought under containment. Currently, details about the cause of the fire are unknown.

Fire containment

What does it mean for a fire to be 50% contained?

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