The Sandalwood Fire in Calimesa was 100 percent contained late on Monday night, according to a post shared on Cal Fire’s Facebook. The flames destroyed 1,011 acres of land before it was stopped.

However, as authorities managed to fight off the Sandalwood Fire, two more fires sparked in Riverside County.

In the town of Oasis, the Johnson Fire erupted after vegetation caught fire on Monday, affecting about 30 acres of land while just a few miles away in Thermal, the Martinez Fire, caused by debris, covered roughly 20 acres of land. Thirty percent of the Johnson Fire was contained as of Tuesday morning, while responders had yet to contain any of the Martinez Fire.

Meanwhile, the Saddleridge Fire, perhaps the biggest and most destructive fire of the season so far, raged on. Cal Fire said the Saddleridge Fire was only 44 percent contained by Monday night. The flames spread across nearly 8,400 acres of land, destroying an estimated 75 structures and homes. The fire has been to blame for at least two deaths.

The Los Angeles Fire Department on Monday said the Saddleridge fire ignited in an area of land behind voltage transmission tower on Thursday, despite Pacific Gas & Electric shutting down power for nearly two million customers across the state last week. Officials have yet to determine the cause of the Saddleridge Fire, though an investigation is ongoing.

Residents living near the Saddleridge Fire were initially evacuated but were allowed to return home, although they were warned of hazardous air conditions engulfing the area due to the smoke. The South Coast Air Quality Management District (AQMD) monitor alerted residents of unhealthy air conditions with elevated PM 2.5 concentrations—polluted atmospheric particles that latch onto the lungs as a result of chemicals like sulfur dioxide and nitrogen oxides emitted in the air—on Friday. The hazardous air affected dozens of communities extending as far as Malibu Creek State Park to Santa Monica and Pasadena.

While the poor air quality can negatively impact even the healthiest individuals, elevated PM 2.5 concentrations can be fatal for people suffering from heart disease, asthma and other respiratory problems.

The air quality advisories were lifted by Monday, although conditions were still only listed as “moderate” by the AQMD.

There are concerns air quality could weaken as fires continue to burn in Southern California, and residents are advised to avoid contact with ash.

California’s air quality has been an ongoing issue for the state. Officials recently came under fire for failing to implement an efficient system to address the poor air quality—caused by the state’s inability to decrease emissions and pollution from cars—and was said to have “the worst air quality in the United States” in a letter from Environmental Protection Agency chief Andrew Wheeler.

Wheeler sent a mandate to an air official in California in September threatening the state would lose federal funding if it did not develop a new plan to combat emissions and pollution.