PORTLAND – Sgt. Lawrence Roukey of Westbrook, a postal worker who joined the Army Reserve after the Sept. 11 terror attacks, was killed in Iraq during a large explosion while he was performing site security.

Roukey, a 33-year-old father of two, was killed Monday, the Defense Department said. A member of the Lewiston-based 3rd Battalion, 304th Regiment, Roukey had been mobilized as an individual soldier from the unit, according to Maine military officials.

Roukey arrived in Iraq six weeks ago, members of his family said. He was the eighth serviceman with ties to Maine to be killed in Iraq.

His family reacted to news of his death with “shock, terror, you name it,” said his mother-in-law Jane Keller.

Roukey appeared to be one of two soldiers killed in an explosion after a team looking for chemical weapons raided a warehouse in Baghdad. A military spokesman in Maine could not confirm that Roukey died in the warehouse, but those were the only hostile-fire U.S. casualties reported in Baghdad on Monday.

Roukey’s wife, Ryann, was grocery shopping Monday when she returned home to find two military chaplains who broke the news.

Military service was a tradition for Roukey’s family. His father was a Korean War veteran and his grandfather was a career military man.

Roukey served three years in the Army after graduation from Portland’s Deering High School. His sister, Dotty Roukey, said he re-enlisted after the Sept. 11 attacks.

“It was a cause he believed in,” she said. “I told him, ‘Make sure you’re ducking and bobbing.”‘

Roukey served as a corrections officer in Maine and Vermont before being hired for the postal job.

“The pride he felt in the military, he showed it at work,” said Lance Farago, a co-worker at the main post office in Portland.

Gov. John Baldacci has ordered flags to be flown at half-staff the day of Roukey’s funeral. “Losing such a brave Maine citizen is a great tragedy,” he said in a written statement.

Also, U.S. Sen. Olympia Snowe promised to press officials at the Department of Defense to determine what happened, and U.S. Rep. Tom Allen extended his condolences to Roukey’s wife, his 2-year-old son, Nicholas, and his 15-year-old stepdaughter, Sonya.

“The escalation of violence in recent weeks has levied a grim toll in death and injury,” Allen said in a written statement. “The American people remain steadfast in our support for the men and women of our Armed Forces.”

Meanwhile, a funeral service is scheduled Saturday in Portland for Spc. Christopher Gelineau, 23, an Army National Guard soldier who was fatally injured last week in an ambush in Mosul in northern Iraq.

Funeral services will be held at the University of Southern Maine’s Sullivan Fitness Center.

Gelineau was a senior at USM and a member of the 133rd Engineer Battalion, which was activated late last year and sent to Iraq in March.