An explosion on a road in northern Iraq hit home hard Wednesday.

Twenty-four hours after cryptic reports of death and injuries began spreading among families with loved ones in the Maine Army National Guard’s 133rd Engineer Battalion, the official announcement was blunt – and specific:

Killed was Spc. Christopher D. Gelineau, a 23-year-old University of Southern Maine student from Portland.

Injured were a roofer from Union, a telecommunications specialist from Pittsfield and a former track star from Portland. Each of the three is recovering, but their families on Wednesday expressed a mix of anxiety and pride.

Gelineau was killed when a homemade bomb exploded beside his vehicle while he was traveling with an Army convoy on Tuesday morning.

The convoy was attacked in an ambush in the northern city of Mosul. The soldiers were riding in the lead vehicle when the bomb detonated.

When the attackers began shooting, the Maine troops fought back and killed or wounded four attackers.

An Army medical helicopter evacuated the two most seriously wounded soldiers to a nearby field hospital. Gelineau was flown to a military hospital in Baghdad and was dead on arrival. The other soldier underwent surgery and was listed in stable condition.

A woman who answered the phone at the Gelineau home Wednesday declined to comment, but a professor at USM, where Gelineau was one semester shy of a degree in information technology, called him an outstanding student.

Wounded in the same attack were Spc. Dwight Emery Nickles, 22, of Union, Spc. Craig Ardry, 30, of Pittsfield, and Spc. Sok San Pao, 22, of Portland.

Nickles suffered a concussion and blown eardrum. Ardry will need a second round of surgery on one of his legs. And one of Pao’s pantlegs caught on fire during the attack.

Vuthi Pao, the sister of Sok San Pao, said her brother suffered neck and back strain in the blast but was not wounded. She said he was treated and had been placed on light duty.

“I talked to him today and he’s doing good,” Vuthi Pao said when contacted at her Portland home Wednesday. “He was in the front passenger seat and was thrown around when the bomb went off. He was able to get out and return fire. His leg caught on fire from the explosion, but it didn’t hurt the skin. His uniform protected him.”

A 2001 graduate of Deering High School, Sok San Pao ran track and is aiming for study in business school.

His sister said she was concerned for all the members of the 133rd. She said their mission was difficult and that while many “probably don’t want to be there, they are doing what they have to do. I’m very proud of them.”

Craig Ardry and his wife, Nanette, have a 2-year-old child and are expecting another one. They were high school sweethearts at Maine Central Institute in Pittsfield. Craig Ardry graduated in 1991.

While in Iraq, he was one of 25 soldiers who served at a former presidential palace in Mosul, although they are now stationed at Camp Marez. He was a driver and had served active duty in the Army from 1991 to 1995.

Dwight Nickles joined the Maine National Guard in his senior year of high school, his father said Wednesday.

He works for a roofing company in Rockport.

In announcing the names of the victims Wednesday, Gov. John Baldacci described the men as heroes.

“We are proud of the way they and the rest of the 133rd have served our state and our nation. All of Maine joins with the families of the injured and fallen soldiers in expressing our great sadness.”

The governor telephoned the families of all four of the men and ordered flags to be flown at half-staff to commemorate Gelineau’s death on the day of his funeral.

There are about 500 Maine soldiers stationed with the 133rd in Iraq. It’s a heavy equipment and transportation unit.

They arrived in mid-March and have been working on construction projects since.

In the hours after the attack, the Army allowed members of the unit to communicate with families but not to identify those who were hit.

Some family members in Maine learned of the attack before the news was reported by the media, while others were taken by surprise when they heard the initial news reports.

Belfast Police Chief Allen Weaver, whose son, Sgt. Allen Weaver Jr., 24, of Belfast, is on his second tour in Iraq, said he learned of the 133rd’s casualties by e-mail.

“He told me that ‘some bad stuff’ happened and that the action was heavy,” Weaver said Wednesday. “I know the news reports create anxiety for some, but I think the military notifies the families relatively fast. But sometimes the news is quicker.”

Debra Francis, whose husband, Sgt. Mike Francis, 43, of Indian Island, is with the 133rd, said she learned Maine soldiers were injured when her mother-in-law called from Missouri on Tuesday night.

“We have family all across the country, and everybody was calling,” said Francis. “It was very scary. We have an 8-year-old at home, and she overheard things and was getting upset.”

Francis said the instant messages offer little comfort. “There is an eight-hour [time] difference. It’s his day when you go to bed and it’s hard to do that, knowing that when you wake up in the morning something could have happened.”

NEWS Reporters Leanne M. Robicheau and Doug Kesseli and The Associated Press contributed to this story.