GROOM, Texas (AP) – Dense smoke from a raging 300,000-acre wildfire reduced visibility on a Texas Panhandle interstate, leading to a multi-vehicle crash that killed four people and injured six, officials said.

The blaze – which rivals in size the fires that blackened thousands of acres of grassland and killed three people in late December and early January – forced the evacuation of eight towns, said Warren Bielenberg, a spokesman for the Texas Forest Service.

“This is probably one of the biggest fire days in Texas history,” Bielenberg said.

The crash involved nine vehicles on Interstate 40 near Groom, about 40 miles east of Amarillo.

“Somebody stopped because of the smoke and, of course, another vehicle hit them and another vehicle hit them,” said Daniel Hawthorne, spokesman for the Department of Public Safety in Childress.

After the crash, officials closed an 89-mile stretch of Interstate 40 because of the low visibility, Hawethorne said. Traffic was initially diverted to U.S. 287 but that highway was later closed because of fires as well, he said.

Winds gusting upward of 55 mph kept water-dropping planes and helicopters grounded when the blazes began Sunday morning, Bielenberg said.

Mandatory evacuations were issued for the cities of Lefors, Skellytown, Miami, Wheeler, Hoover, McLean and Old and New Mobeetie, he said.

A separate 70,000-acre grass fire burned Sunday in nearby southeastern New Mexico, prompting evacuation orders for up to 200 people and injuring one man.

The fire burned the post office in McDonald, N.M., and several other buildings, officials said. A state road was closed and residents in McDonald and Prairie View, N.M., were told to leave their homes.

A man who suffered burns while trying to put out the fire was taken to a Lubbock, Texas, hospital where he was in stable condition, officials said.

Authorities didn’t know what sparked the blazes in either state.