Traffic is back to normal on I-285 in southwest Atlanta after a fiery wreck between two tractor-trailers shut down northbound lanes for more than three hours this morning.

All lanes of I-285 at Cascade Road are now open with the wreckage off to the right shoulder, according to the Georgia Department of Transportation.

The accident was reported just past the Cascade Road exit around 4 a.m., fire officials said.

Neither truck driver was hurt, but authorities believe that one of the drivers may have been asleep at the wheel.

“It would appear that the driver (who initiated the wreck) fell asleep somehow,” Fulton County Fire Department Deputy Chief Jack Butler told The Atlanta Journal-Constitution.

The truck hit another 18-wheeler that had been parked on the shoulder with apparent mechanical issues, authorities said.

“He made contact with another tractor trailer and hit him from the back, ripping his saddle (fuel) tanks in the process, and coming to rest … on the guard rail,” Butler said.

The first truck burst into flames, and the fire spread to the second trailer, which was hauling flammable household cleaners, he said.

Firefighters were able to extinguish the flames and a hazardous materials unit “worked to try to keep any of the runoff and fuel out of the drains,” Butler said.

Traffic piled up on the northbound lanes as far as Langford Parkway, according to traffic reporters with AM 750 and 95.5 FM WSB News/Talk Radio.