The southbound lanes of Interstate 35W were closed at Meacham Boulevard Wednesday morning due to a crash involving an 18-wheeler.
According to MedStar, four people were sent to the hospital as a result of the crash, which appeared to involve an 18-wheeler and at least three other vehicles.
Drivers were left stuck in the backup for up to two hours. At one point, crews opened one lane to let hundreds of cars pass the wreck.
All lanes were reopened by 10 a.m.
At this time, no further information is being released.