Updated: 9:48 p.m. Sep. 14

First discovered: 12 days ago, 4:05 p.m. Sep. 2

Initial location: Multiple locations across Calaveras, Tuolumne County, San Joaquin County and Stanislaus County, Calif.

Fire unit: Cal Fire Tuolumne-Calaveras Unit

Fire type: Wildfire

Fire name: Tcu September Lightning Complex

The wildfire initially started 4:05 p.m. Sep. 2 in Calaveras, San Joaquin, Stanislaus, Tuolumne County, California.

After being active for 12 days, the wildfire has burned 13,869 acres. The fire crew managed to contain the fire entirely by Sunday evening. It is assumed that a lightning strike started the fire.

Historic data

NIFC statistics for 2023 indicate that lightning was responsible for 305 fires in California, with 90,206 acres of wildland burned.

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 firefighters have managed to get a line completely around the wildfire’s perimeter 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