In Iron Man, how did Tony Stark get injured?

Tony Stark was on his way to a weapons presentation when the army car in front of him exploded. Then Tony saw as the men were killed right in front of him. Tony ran out of the car, dove behind a rock, and started texting on his device. Then a bomb that had the words: "Stark Industries" on it landed a few feet away from Tony and Tony decided to put himself in danger and tried to retrieve the bomb. The bomb exploded, sending shards of shrapnel into his chest. He has been in captivity for 3 months.

Mr. Anthony "Tony" Stark was going to a weapons presentation in Afghanistan when the army car in front of them exploded, having the fight be caused by the 10 Rings. The men that are a part of the 10 Rings captured Tony and demanded him to make them the Jericho missile that he had created by himself. Tony refused to make the missile for them, and as a punishment, he was dunked in water 2 times. Tony had suffered a very scary injury: A electromagnet connected to a car battery because of the explosion blast that killed the men that were protecting Tony. After 6 months of captivity in Afghanistan, Tony had made weapons for them to protect them from bad guys. He said that he was going back to finish off the 10 Rings for stealing his weapons. Check Wikipedia for the full plot.