Thirteen people including firefighters injured in ‘hellish’ California wildfires

As least 13 people have been injured in three major southern California wildfires that broke out this week during a scorching heatwave. Firefighters battling the blazes, already stretched to the limits by a challenging summer, were among the injured.

Related: ‘Exceptionally difficult’: grueling wildfires test the resolve of US crews

The Bridge fire in the Angeles national forest, located north of Glendora, exploded from about 4,000 acres (1,600 hectares) on Tuesday to 34,000 acres that evening, according to the Los Angeles Times.

At least 33 homes and six cabins have been destroyed by the Bridge fire, authorities said, adding that the fire is currently threatening 2,500 buildings in an area strapped for personnel with so many fires raging at once.

“As a region, we’re currently at drawdown for fire personnel and resources,” said Anthony Marrone, the Los Angeles county fire chief, adding that authorities have requested assistance from northern California and nearby states.

In Orange county, firefighters did battle with a fast-spreading fire that ignited on Monday and has since sprawled to more than 19,000 acres. This blaze, called the Airport fire, was caused by a spark from heavy equipment that was used by public workers, according to officials.

The fire had spread into the mountainous region of adjacent Riverside county with no containment. Two firefighters endured heat-related injuries and a resident suffered from smoke inhalation.

Acres burned

US wildfires are measured in terms of acres. While the size of a wildfire doesn’t necessarily correlate to its destructive impact, acreage provides a way to understand a fire’s footprint and how quickly it has grown.

There are 2.47 acres in a hectare, and 640 acres in a square mile, but this can be hard to visualise. Here are some easy comparisons: one acre equates to roughly the size of an American football field. London’s Heathrow airport is about 3,000 acres. Manhattan covers roughly 14,600 acres, while Chicago is roughly 150,000 acres, and Los Angeles is roughly 320,000 acres.

Megafire

A megafire is defined by the National Interagency Fire Center as a wildfire that has burned more than 100,000 acres (40,000 hectares).

Containment level

A wildfire’s containment level indicates how much progress firefighters have made in controlling the fire. Containment is achieved by creating perimeters the fire can’t move across. This is done through methods such as putting fire retardants on the ground, digging trenches, or removing brush and other flammable fuels.

Containment is measured in terms of the percentage of the fire that has been surrounded by these control lines. A wildfire with a low containment level, such as 0% or 5%, is essentially burning out of control. A fire with a high level of containment, such as 90%, isn’t necessarily extinguished but rather has a large protective perimeter and a rate of growth that is under control.

Evacuation orders and warnings

Evacuation warnings and orders are issued by officials when a wildfire is causing imminent danger to people’s life and property. According to the California office of emergency services, an evacuation warning means that it's a good idea to leave an area or get ready to leave soon. An evacuation order means that you should leave the area immediately.

Red flag warning

A red flag warning is a type of forecast issued by the National Weather Service that indicates when weather conditions are likely to spark or spread wildfires. These conditions typically include dryness, low humidity, high winds and heat.

Prescribed burn

A prescribed burn, or a controlled burn, is a fire that is intentionally set under carefully managed conditions in order to improve the health of a landscape. Prescribed burns are carried out by trained experts such as members of the US Forest Service and Indigenous fire practitioners. Prescribed burns help remove flammable vegetation and reduce the risk of larger, more catastrophic blazes, among other benefits.

Prescribed burning was once a common tool among Native American tribes who used “good fire” to improve the land, but was limited for much of the last century by a US government approach based on fire suppression. In recent years, US land managers have returned to embracing the benefits of prescribed burns, and now conduct thousands across the country every year.

Nearby, approximately 65,000 homes and buildings were threatened by a wildfire raging in the San Bernardino national forest. The Line fire charred more than 27,000 acres by Tuesday evening, consuming expanses of brush, and remained a mere 14% contained on Tuesday night, according to reports.

Authorities arrested and charged a 34-year-old man with arson for allegedly starting the fire, according to the San Bernardino county sheriff’s department. Officials did not specify what had been used to start the blaze.

The three sprawling fires, which spurred doomsday-like smoke plumes around the greater Los Angeles area, came as other areas of the US west battled powerful infernos, such as near Reno, Nevada, where about 20,000 people evacuated.

So far this year, California has seen nearly three times as much acreage burn than during all of 2023.

Flames from three wildfires have blackened once-green landscapes, leaving barren, leafless trees in their wake.

Alex Luna, a 20-year-old missionary, saw the sky turn from a cherry red to black in about 90 minutes as flames raced toward his mountain community of Wrightwood, and authorities implored residents to leave their belongings behind and get out of town.

“It was very, I would say, hellish-like,” Luna said on Tuesday night. “It was very just dark. Not a good place to be at that moment ... Ash was falling from the sky like if it was snowing.”

Luna was among those who heeded the evacuation order that was issued for the community of about 4,500 in the San Gabriel mountains east of Los Angeles. The Bridge fire, which grew tenfold in a day, is now the largest of three major wildfires burning in southern California and endangering tens of thousands of homes.

The fires are burning near mountain towns and lakes that are popular for winter sports and summer recreation. Evacuation orders were expanded on Tuesday night as the fires grew and included parts of the popular ski town Big Bear.

For Wrightwood, a picturesque town located some 60 miles (97km) east of Los Angeles, threatening wildfires have become a regular part of life. But for Janice Quick, the president of the Wrightwood Chamber of Commerce, something felt different this time.

She told the Associated Press she had been texting with friends, one of whom said a friend’s home had been consumed by fire, while another friend watched through her Ring camera as embers rained down on her home.

“I’ve never seen anything like this, and I’ve been through fires before,” said Quick, a 45-year resident of Wrightwood.

Southern California has reeled from a record-breaking heatwave since late last week, with temperatures soaring well above 100F (38C) and creating conditions for unchecked wildfires. An excessive heat warning for the Los Angeles area ended on Tuesday night, and firefighters hope to win an advantage as cooler weather reaches the state later this week.

Across the west, authorities in states battling wildfires took steps to protect residents. The Nevada governor issued an emergency declaration, while fire managers in Idaho braced for warm, dry and windy conditions as the Boulder and the Lava fires burned in western Idaho. Several fires spurred evacuation warnings in central Oregon.