At 04:49hrs units were dispatched to the reported MVA in the area of US59 southbound and W. Airport. As units were responding WestCom advised of a corrected location closer to US59 and W. Bellfort, in the City of Houston, and that vehicles were reported on fire. As this was being transmitted Battalion 21 advised of a column visible and directed Engine 22 to access the main lanes and for Truck 21 to take the feeder road. Upon arrival a 3-vehicle accident was found with 2-passenger cars on fire on the main lanes and a 18-wheeler totally involved on the feeder road after leaving the elevated portion of the freeway. With HFD units on scene, Engine 22 began fire suppression on the freeway while Truck 21 assisted on the 18-wheeler. Upon arrival of HFD foam units Stafford units assisted until released approximately 1-hour later. The circumstances and cause of the accident are under investigation by the Houston Police Department.