Delta fire continues to close large stretch of I-5.

The Delta fire burning in Shasta County has grown tomore than 15,000 acres overnight after exploding in size Wednesday evening, continuing to close a large stretch of Interstate 5 in both directions, U. S. Forest Service officials reported Thursday.

The fire grew “aggressively” overnight, with “flame lengths estimated at 300 feet high,” according to a 9 a.m. incident update by the U.S. Forest Service.

Burning north of Lakehead and about 10 miles away from Redding, the Delta fire started about 1 p.m. Wednesday, consuming bush and timber at a “critical rate of spread,” Shasta-Trinity National Forest spokesman Joe Orosz said.

The blaze quickly grew to 5,000 acres within hours, officials reported as of Wednesday’s last update. By Thursday morning’s incident report, the fire was mapped at 15,294 acres with no reported containment.

Evacuation orders are in place for the areas along the I- 5 corridor on both sides, between Lamoine up to the Shasta- Siskiyou county line, and all residents of Dunsmuir. An evacuation center has been established at theMt. Shasta Community Center, 629 Alder St. The Mount Shasta Humane Society is accepting small animals of evacuees, at 1208 N. Mount Shasta Blvd.

Shasta-Trinity National Forest spokesman Chris Losi said about 300 civilians have been evacuated and 300 structures are threatened, including 150 residences.

“There’s not a lot of people there normally and a lot were evacuated, so that’s good,” Losi said.

The fire closed I-5 from 10 miles north of Redding at Fawndale Road to 5 miles south of Mount Shasta at Mott Road, Caltrans said Wednesday — a stretch of nearly 50 miles that is still closed as the fire continues to grow.

Media reports and videos posted to social media show that more than a dozen big rigs were abandoned along the freeway Wednesday. Lt. Cmdr. Kyle Foster of the California Highway Patrol’s Mount Shasta office told the Los Angeles Times that at least four had caught fire Wednesday.

A U. S. Forest Service incident report says high temperatures and midday gusts of 15 to 20mph were expected Thursday. Smoke fromthe fire is expected to spread through Northern California.

Fire officials have indicated that the Delta fire is human-caused, but did not give further details.

California Interagency Incident Management Team 5 is managing the Delta fire, as well as the Hirz fire, burning about 3 miles away.

The Carr fire, which killed eight people and devastated parts of Shasta County in the Redding area, reached 100 percent containment Aug. 30.