SAN FRANCISCO (Reuters) - Jordan Towers said he was unpacking a truck during a family move from Truckee, California, to the state capital of Sacramento when he heard the news that a plane had flown into New York's World Trade Center.

"It sounded like a radio DJ hoax," Towers said. "Then I turned on my TV, and the second plane was hitting."

For Towers, then a 17-year-old high school student, the September 11, 2001 attacks changed his life.

He said he already had been considering joining the Navy as a way of financing college. After the attacks, he said he decided to enlist in the U.S. Marine Corps instead because he would be more likely to fight the enemy directly as a Marine.

"It was 9/11 that really convinced me that I had to do something," he said. "There was anger in me. I didn't know who the Taliban was, but I knew they were the enemy and I had the sense I wanted to kill these people for attacking us."

Afghanistan's Taliban rulers had harbored the al Qaeda leaders responsible for 9/11 and the United States invaded Afghanistan just weeks after the attacks. In 2003, the United States also invaded Iraq.

Towers was deployed to Iraq in 2007. His unit was supposed to detect movement of people trying to plant roadside bombs, a weapon of choice for insurgents fighting U.S. troops in Iraq.

"We were just sitting ducks," Towers said. "I didn't know who the enemy was. I never thought I was doing the right thing over there. I never thought that I was helping people."

In spite of being shot at, he came home in one piece and did not lose any close comrades. Since returning home, he has sought treatment for post-traumatic stress disorder (PTSD) from U.S. Department of Veterans Affairs doctors, as thousands of other returning U.S. troops have done.

He said he is still recovering from his military service. He attends college and works for a group that aids veterans with needs like jobs and housing, Swords to Plowshares.

"The war is always on my mind," Towers said. "I'm surprised when I walk into San Francisco coffee shops and everyone is drinking coffee and they're acting like we're not fighting two wars. There are young people over there who are really sacrificing so much, putting their hearts into this belief that they should be there. I feel like Americans just don't care."

(Reporting by Laird Harrison; Writing by Alex Dobuzinskis; Editing by Arlene Getz and Will Dunham)