Monday started as a quiet day in Baghdad. Army Spc. Darrell Green, 38, and his platoon were on security patrol.
"In the afternoon, I took up my position on the sixth floor of the Sheraton Hotel overlooking the traffic circle," Green said.
Later that afternoon, three huge car bombs exploded in the space of four minutes. The target: two hotels filled with Western journalists and contractors.
Seventeen people were killed, but the toll and the damage could have been much worse. From his vantage point, Green saw the first two bombs go off. He noticed a huge hole in a concrete barrier surrounding the hotels, and then he saw a large truck.
"A cement mixer was trying to come through our perimeter," Green said. "Once the dust settled, I engaged that vehicle before it got to the hotel and subsequently stopped the driver from making it in between the two hotels."
Green was about 100 yards away.
"I had a machine gun," said Green. "I fired several bursts into the truck itself, therefore stopping the driver. Once the vehicle stopped, the vehicle exploded. It knocked me off my feet."
Some have compared the blast to the bomb that destroyed the Murrah Federal building in Oklahoma City. Green's quick thinking and marksmanship saved hundreds of lives.
"If that vehicle had a made it up in between those two hotels, there would have been a lot of death and destruction," Green said. "I am just glad we were just able to stop him."
Green has been in the army for six years, the last 10 months spent in Iraq on his second tour of duty there. Like so many soldiers, he is devoted to his job, and misses his family.
"I have a beautiful wife," he said. "I've been with her for going on 12 years. I have a 12-year-old son, Matthew; a 7-year-old son, Jacob; a 5-year-old son, David. They're great. I have a wonderful loving family who really wants me to come home."
Home for Green is near Orlando, Fla., where he was born and raised. His tour was scheduled to end this week, but it has been extended to January.
"He did something great, and I couldn't be more proud of him," said Green's wife, Dawn. "My biggest concern is that I just want him home, and I want him safe."
"I always pray for him that he'll always be all right, come back home safe," said his son, Matthew.
Matthew calls his dad a hero. His dad disagrees.
"This really isn't about me, I don't think," Green said. "As far as being a hero, I'm not a hero. I was doing my job at the time. And everybody here that was in the military -- whether it be Navy, Marines, Army, what have you -- we're all heroes, and that's what we've got to look at. We've lost too many lives. And those are the real heroes."
When Green finishes this tour of duty he is planning to retire from the Army. He wants to become a policeman and hopefully one day, a detective.
ABC News' Bob Woodruff filed this report for "World News Tonight."