My wife and I were driving to Galveston on I-45 and were driving through La Marque when our car suddenly lost power. I started moving over to the outside lane and went to turn on the emergency lights. I realized the lights were already on. We heard a thump and thought that the serpentine belt had broken and that the engine would overheat, followed up by white smoke coming from the dash vents. My wife opened her window and leaned out the window while I tried to control the SUV without power. A truck pulled next to us and the passenger screamed that our car was on fire. I stepped on the brakes, but my foot went to the floor without effect. I hit the button for the emergency parking brake, but it didn't stop the car. I let the car slow down and then black smoke was coming from the vents. We were choking from breathing the smoke and I tried to open my window, but all electrical systems had quit working. The car finally slowed enough for me to shove the gear shift into park. My wife jumped out of the car and fell to the pavement, also hitting the concrete barrier on the side of the highway. My seat belt was stuck and I kept pushing the button and reached for my pocket knife to cut the belt when it released. At this point, flames were coming from the vents when I reached for the door handle and open the door. I fell out of the car onto the highway, rolling away. I was finally able to get up and saw several vehicles stopped behind us, but some were still driving through. I got away