Savannah Now -- Col. William Wood was witnessing progress in Iraq first-hand, and writing home about it.

In one of his last e-mails, the 3rd Infantry Division officer told his father how he stayed awake for 40 straight hours leading up to last month's constitutional referendum, delivering ballots to polling stations after Iraqi contractors refused the job.

"He said the Iraqis were excited about going to vote," said Wood's father, Jimmy Wood of Panama City, Fla. "He died serving his country. He died doing what he wanted."

Wood, commander of the 1st Infantry Battalion of the 184th Regiment, a California Army National Guard unit, was killed in Baghdad on Thursday. He was responding to a roadside bomb, ordering his men to secure the area when a second explosion took his life, the Army said Monday.

Wood, 44, is the highest ranking Army officer to be killed in Iraq. At the time of his death, Wood wore the rank of a Lieutenant Colonel. He was unaware he had been promoted to Colonel, an advancement only about 40 percent of Lieutenant Colonels achieve in the Army.

"They keep those promotions very close to the vest," said Jimmy Wood, fighting back tears. "He would have been elated, as well as I would have."

The promotion was awarded to Wood posthumously, said 3rd ID spokesman Lt. Col. Cliff Kent.

Jimmy Wood, who is retired from the Air Force, said military careers run in the family. After graduating from Florida State University in 1984, his son joined the Army and worked his way up through the ranks.

"He was a people person and a soldier's soldier," Wood said, describing how his son asked to be transferred from a deputy chief of staff position, a desk job, to commanding soldiers.

"He wanted to be where the action was. That was the type of person he was," Wood said.

Wood, a Panama City native, is survived by his wife and 13-year-old daughter who live in Hinesville.

His death brings the total number of U.S. military deaths to 2,026 since the Iraq war began.