This is the terrifying moment a gigantic tornado sweeps past a hapless motorist in Illinois, who films it from his truck. The driver, Sam Smith, begins filming with the tornado just a few hundred yards in front of him. It's an apocalyptic sight - and Mr Smith feels trapped, because he can't make out which direction it's moving in so doesn't know how to escape. This is the terrifying moment a gigantic tornado swept past a hapless motorist in Illinois, who filmed it from his truck . The driver, Sam Smith, begins filming with the tornado just a few hundred yards in front of him . Harrowing: It then passes right in front of his truck - while Mr Smith spoke to his son on the phone . He says on the video: 'This is a tornado and I cannot tell which way it is going. So I don't know how to get away from it. But it looks like it's coming right towards me.' Sounding remarkably calm, he continues: 'Yep, it's going to come right over me. Let's see if I can back up a little bit and get under the bridge. Yeah, it's coming right over me. 'Oh c**p. I've never been in a tornado before. Totally crazy. It's coming right over the top of me. It's a little bit scary. 'I don't really know what to do except I guess just sit here. Maybe duck down. Oh my gosh. That's crazy. Crazy, crazy. Holy smokes. The truck feels like it's about to lift up off the ground.' The tornado blows debris across the road in front of Mr Smith's truck . As the tornado sweeps past Mr Smith says that the truck felt like it was going to lift off the ground . Mr Smith was travelling from Minneapolis to Indiana on business last Thursday when the harrowing encounter took place . Mr Smith said afterwards that he hung up on his son so he would think they were disconnected as 'it seemed things were going to get real bad' Fortunately the tornado passes leaving Mr Smith unharmed and his truck intact, but the footage clearly shows that it was a close call. Mr Smith was travelling from Minneapolis to Indiana on business last Thursday when the harrowing encounter took place. He said afterwards: 'There was heavy rain and I saw cars pulling off the side of the road. I thought it was because they did not want to drive in heavy rain. Then it started hailing very large golf ball-sized hail. I thought the truck would be dented so I pulled off the road under and over-pass with several other vehicles. 'As I was leaving that over-pass my son called and I answered. It was then that I saw the tornado far off in the distance. He was excited and asked me to record it. So as I approached the next over-pass I pulled under it. 'Having no idea it was coming right my way. I continued to film and backed my truck further under the over-pass. As it got closer and closer I realized it was most likely going to hit me. I remained calm since I had my son on the phone. As it got closer it seemed likely things were going to get real bad and so I hung up on my son without saying goodbye so he would think we just got disconnected. The video tells a pretty good story from there.' According to the Storm Prediction Center in Oklahoma, Mr Smith should not have backed his car under a bridge when he caught sight of the tornado. It says on its online tornado safety guide that if you're in a vehicle when one comes near that you must 'avoid seeking shelter under bridges' as it can create 'deadly traffic hazards while offering little protection against flying debris'. It continues: 'There is no safe option when caught in a tornado in a car, just slightly less-dangerous ones. If the tornado is visible, far away, and the traffic is light, you may be able to drive out of its path by moving at right angles to the tornado. 'Seek shelter in a sturdy building, or underground if possible. If you are caught by extreme winds or flying debris, park the car as quickly and safely as possible - out of the traffic lanes. Stay in the car with the seat belt on. Put your head down below the windows, cover your head with your hands and a blanket, coat, or other cushion if possible. If you can safely get noticeably lower than the level of the roadway, leave your car and lie in that area, covering your head with your hands. If you're in a mobile home it strongly advises to leave immediately and to head to the basement if you live in a house that has one. If you're in a building with lots of glass occupants should go to a windowless room on the lowest floor possible, the guide says.
Extraordinary footage taken by driver on business trip to Indiana.
The driver describes how the situation is 'totally crazy' as he films.
He was talking to his son on the phone at the time, so tried to sound calm.