Update: All Lanes Open After Tractor Trailer Fire Shuts Down Part Of 66 West

Update 6:25 p.m.: All lanes on I-66 are now open.

Update 6:08 p.m.: The left lane of Interstate 66W is now open.

Update 5:27 p.m.: The 66 closure has also created backups onto several local roads, including a jam on Chain Bridge Road that stretches several miles westbound through Vienna and Oakton.

Nutley Street, which runs from the Vienna metro toward Vienna and Fairfax, was also not moving.

On 66, Twitter user fenriswolfkpc said "It looks totally clear ... until I hit Nutley Street and the Vienna Metro."

Update 4:37 p.m. Twitter user Map408psu reported that crews are still clearing debris from the road.

Update 4:09 p.m.: Photos taken by Patch at the scene show debris scattered across the road, and several fire trucks still on scene.

Update 3:50 p.m. Fairfax County says traffic is being diverted to exit 60, and onto Chain Bridge Road (Route 123). Delays are now extending back about 4.5 miles to tbe beltway. 

Update: 3:46 p.m. Officials expect the road to be shut down for at least another one to two hours.

Commuters should take Routes 29 or 50, or another alternate route, into Virginia.

Update 3:20 p.m.: Onramps from 123 to 66 W are being used instead to get cars off of 66.

Update 3:05 p.m.: The exits with the most backup appear to be for Route 123, on both the eastbound and westbound sides.

2:50 p.m.: An early afternoon tractor trailer fire is shutting down I-66 Westbound for about an hour.

Fairfax County Fire Capt. Willie Bailey said hay on the truck caught fire at about 1:45 p.m. Tuesday. The incident caused no injuries, but the hay is still smoldering, he said.

The cause of the fire is still unknown, he said.

The tractor trailer is just before Lee Jackson Highway. The road is shut down starting at Route 50, but has been backed up past Vienna at certain points throughout the afternoon and I-66 E is also moving slowly, some witnesses say.

Elizabeth DiFrancisco was driving eastbound on 66 around 1:50 p.m. Tuesday when she saw the incident just past the exit for Oakton. She said it appeared the cab was able to detach from the truck, and "it looked like it was a spontaneous combustion."

"It was really blazing," said DiFrancisco, who was returning from Wegmans with her daughters. "The flames could be seen above the overpasses."

Patch will update this story as more information becomes available.