Updated: 7:32 p.m. June 24

First discovered: 5:44 p.m. June 24

Initial location: 4400 block of Petersen Road, Suisun, Solano County, Calif.

Fire unit: Unified Command: Cal Fire Sonoma-Lake-Napa Unit and Fairfield Fire Department

Fire type: Wildfire

Fire name: Petersen Fire

Petersen Fire initially started today at 5:44 p.m. on 4400 block of Petersen Road, Suisun in Solano County, California.

As of Wednesday evening, a fire crew of 43 has achieved full containment of the fire. Investigations into its cause are still ongoing.

According to Cal Fire, “Numerous firefighting air tankers from throughout the State are flying fire suppression missions as conditions allow.”

Fire containment

What does 100% containment mean?

Note that full containment doesn’t mean the fire is completely out. In this case, it means that the whole perimeter of the wildfire has been surrounded by a control line and it is now stopped from spreading. A fully contained wildfire may continue to burn within the containment perimeter but is not likely to spread.

However, there’s a significant difference between containing and controlling a wildfire. After the fire is fully contained, the next step is to control it. Controlling a fire means ensuring that the fire can’t spread or cross the containment line.

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