On Jan. 20, Major Thomas Shields had no idea he would stumble upon the fatal crash on Pontiac Trail that killed Pedro Montanez and one of his sons.
Montanez, 36, either hit black ice or a pot hole, killing him and his 9-year-old son Steven. Two other children, Michael, 10, and Valencia, 6, survived, thanks to Shields.
"Nothing would prepare you to take a right turn and arrive at this scene," he said.
Montanez was driving his children to school when his vehicle slid over the center line and hit a truck head-on, in South Lyon.
Shields, an active duty U.S. Marine, was the first motorist to come across the scene.
"As I walked up to it, it was all very quick assessments," he said.
Shields relied on training from a tour of duty in Iraq. He found Michael with his mouth full of blood.
"He was having a hard time breathing," Shields said. "Basically I cleared his air way. I reached in and grabbed everything that I could, to clear his airway."
Valencia had broken bones, but still breathing - and freezing.
That was when Shields called a bystander over.
"I said you have to take this little girl from me," Shields said. "When he did, he said 'What do I do?' I said I have a coat in that car. Wrap a coat around her, she's probably very cold. I was concerned about shock and that sort of stuff. And he ends up putting her in my car."
The children were rushed to C.S. Mott's Children's Hospital in Ann Arbor at the University of Michigan. They remain hospitalized but both are improving.
Shields gave Michael a personal item to help in his recovery - an item he carried with him in Iraq.
"During my last tour, my father-in-law is a Vietnam veteran and someone I look up to immensely, gave me this little coin," Shields said. "It had something about a guardian angel on it and it has my name on it. I carried it in my left pocket, that and three rocks my son gave me on a beach in California one day. But I carried those in my left pocket no matter what I did, or what set of clothes that I wore.
"When I was at the hospital, I asked their mother if I could give it to her to guard him at this point in time, as we take this one day at a time."
Shields said he is not talking about the incident for publicity. Public safety sources tipped FOX 2 that Shields was at the scene and first responders said he was responsible for saving Michael and Valencia.
Shields said he did not know the family at all but he's gone to the hospital, met the mother and the two children are doing well.