Interstate 5 in Southern California freeway was nearly fully reopened as firefighters boosted their efforts to counter the blaze on Sunday.

The California Highway Patrol restricted movement on the busy highway after the fire moved through the Castaic’s mountainous terrain and grew to the size of nearly 450 acres. US media reports also suggest that at least two firefighters sustained burn injuries.

The United States Forest Service said that firefighters were making “good progress” against the blaze using aggressive ground attack strategies and helicopters, which have been frequently dropping water on the fire.

Meanwhile, residents of South Lake Tahoe continue to wait for a chance to visit their neighborhood to inspect the damages sustained due to the Caldor Fire, which burnt for weeks in the state of California. Most of Grizzly Flat’s homes, as well as the school, post office, church and fire station, were destroyed in the first days of the fire, according to reports from Associated Press.

Those who have underlying health problems have been advised to delay their return to the Lake Tahoe residences as the air quality is not at its best in the area. However, Fire Chief Clive Savacool said officials hoped to have the hospital emergency room open within 24 hours, according to reports from Associated Press.  

Firefighters were diverted from battling the 342-square-mile (886 square kilometer) wildfire to fight multiple overnight lightning fires when thunderstorms swept across the state Thursday night into Friday.

The state of California has also been battling the Dixie Fire, which was triggered in July this year and has caused substantial damage to the state’s green cover in areas like Sierra Nevada and the southern Cascades. 

However, state officials said that the rain, which partially aided the efforts of firefighters, has now started to try up, leaving the vegetation flammable.

The second-largest fire in California history has burned 1,500 square miles (3,885 square kilometers) of land and more than 1,300 homes and other buildings. It was 65% contained.

(With AP inputs)