A U.S. Marine who was part of the unit that helped rescue Army Pfc. Jessica Lynch (search) died in a car crash on his first weekend home since returning from Iraq.

Josh Speer was killed when his car veered off the road, overturned several times and struck trees Sunday morning. The 21-year-old soldier was heading to see his fiancée.

Capt. Shawn Turner, a Marine Corps (search) spokesman, said Speer served with the Marine unit that aided in Lynch's rescue. Turner said details of what Speer's unit did to help Lynch, the Army private captured by Iraqis, were unavailable.

Speer was wearing his seat belt, state Highway Patrol Lance Cpl. Dan Marsceau said.

Speer's family said he had returned home to Marietta (search) on Thursday. Holly Coupe, his fiancée, said Speer wrote her from Iraq, promising that, "The first thing I do when I get back is put a ring on your finger."

The couple went to a local amusement park over the weekend, but she expected Speer to give her the ring when they were to go hiking next week.

"I lost him, but it's the Lord's will," Coupe said. "It's hard to accept, but I have to. He has bigger plans for him."

William Coupe, Holly's father, said he was proud of Speer. "Out of everybody you want your daughter to marry, he's the guy," he said. "I loved him like a son."