HARRISBURG, Ill. -- A knock on the door before dawn Thursday brought a grim Veterans Day wakeup to this small coal-mining town, in Southern Illinois.

Two uniformed Marines stood outside, waiting to inform Carl Pickering that his only son was dead. Aaron Pickering, a 20-year-old infantryman, had been killed hours earlier as American forces fought to capture the Iraqi city of Fallujah from Islamic insurgents, the family said.

Pickering was the fourth Marine from Illinois to die this week during the U.S. offensive. At least 18 U.S. troops have been killed so far in the Fallujah operation, and 69 more have been wounded, according to military officials.

In a phone call home just last week, Pickering had told his father his unit was preparing for action.

"He said he was fine but that it would be awhile before he could call again because things were about to happen. He was scared but he was like, 'If everybody does their job and I do my job, we'll all be OK,"' said his stepmother, Teresa Pickering.

His death Wednesday was a second heavy blow to his father, a correctional officer and volunteer firefighter who lost his only other child five years ago, when his 17-year-old daughter was killed in a car wreck.

"The grandchildren he would have had he won't have now. So this has really hit him hard," Teresa Pickering said.

Flags were lowered to half-staff as word of Pickering's death spread through his hometown of about 9,000 people. The Marine was remembered with prayers and a moment of silence during a Veterans Day observance attended by about 60 people.

"I was hurt for the family, but I was glad we were able to do this ceremony for them," said Dan Brittain, commander of Harrisburg's American Legion post.

The young Marine's death drove home the Veterans Day meaning "in everyone's heart," said Rick Rice, quartermaster of the Veterans of Foreign Wars post in nearby Eldorado, where Pickering was also remembered.

"It's another fallen comrade. It's never a good day for that," Rice said.

Pickering was a sportsman. He attracted friends easily, his stepmother said, and he played golf, baseball, ran track and loved to hunt and fish. He had followed an uncle into the military, joining the Marines after graduating from Harrisburg High School in 2002.

Pickering was assigned to the 1st Battalion, 3rd Marines, C Company, based in Okinawa, Japan, and "just really loved the Marines," Teresa Pickering said. "He liked the whole military thing."

"Everybody is saying he's a hero," she said. "We were very proud of him. He was not afraid of anything."