Westbound drivers on Interstate 66 in Vienna, Va. Four people have died on the highway since April 2018. (John McDonnell/The Washington Post)

One person was killed and another was seriously hurt in a fiery multi-car crash on Interstate 66 on Saturday morning, closing the Northern Virginia highway in both directions and clogging traffic for miles.

The fatal pileup happened at about 10:55 a.m. in the westbound lanes of I-66 before the exit for Route 28 in the Centreville area, according to Bill Delaney of Fairfax County Fire and Rescue. Virginia State Police said seven vehicles were involved, including a tractor-trailer. Video from a nearby traffic camera captured at least one vehicle fully engulfed in flames.

At least four people have died on I-66 in Northern Virginia since April 2018. A person died in a crash near the Route 123 exit in April 2018, and another died near there five months later. A driver was killed near Bristow in May of this year.

The sequence of events Saturday was not immediately known. In addition to the deceased person, who was not identified, another person was flown out with life-threatening injuries, four people suffered significant but non-life-threatening injuries and one person suffered a minor injury, Delaney said.

Virginia State Police spokeswoman Corinne Geller said the person killed was a passenger in the burning vehicle, and the person flown to a hospital in Washington was the driver. She said the crash was a chain reaction involving four sedans, one SUV, one pickup truck and the tractor-trailer, which overturned.

The state police were still working to confirm the identities of the two people in the burning vehicle Saturday afternoon.

Traffic on I-66 is heavy throughout much of the week and sporadically heavy on weekends. The Virginia Department of Transportation estimated last year that 79,000 cars per day passed through the stretch of I-66 near Route 28 where Saturday’s crash occurred.

In an effort to lighten traffic during the week, Virginia is moving to extend its morning and evening toll portions beyond the Beltway, adding 22 more miles of toll gantries along I-66 out to Gainesville. Construction is in full swing on Route 28 at the entrances to I-66 as part of the “Transform 66 Outside the Beltway” project, a $3.7 billion public-private partnership with Express Mobility Partners.

The burning vehicle appeared to have gone over a jersey wall on the right side of I-66. State transportation officials did not immediately confirm whether the jersey wall was part of the project to expand the toll lanes.

The highway has inspired significant passion among motorists, and not in a good way. In 2014, the state Department of Motor Vehicles found about 100 personalized plates pertaining to I-66, with messages such as “I66 SUXX,” “UDI66,” and “IH8I66.”

Frustrated drivers took to social media Saturday hoping to get an idea of when traffic would clear.

“Is there no way to get one lane by? Hundreds of cars have been parked for 45 minutes,” one commuter asked the Fairfax fire department on Twitter.

“Not at this time,” the fire department responded. “Debris all across roadway. Several vehicles involved.”

“Any idea how long until 1 lane opening?” Adam Mason asked around the same time.

“No. Sorry,” the fire department responded.

Mason, a photographer, was on his way to shoot a wedding when he got stuck in the back up.

“2+ hours,” Mason said in a text. “I was on 66 in standstill for that long.”

Mason, who listened to podcasts while he was stuck watching a plume of black smoke curl through the sky, was an hour late to the wedding but made it just in time for the ceremony.

The eastbound lanes of I-66 reopened by 11:45 a.m., but the westbound lanes remained closed at 5:30 p.m., with drivers being diverted to Fairfax County Parkway.

Correction: This article has been corrected to indicate that 79,000 cars per day travel on I-66 near Route 28, not 21,000, which is the number of people who take the Route 28 exit.