A Sebastopol hay truck driver and longtime California National Guard soldier was killed by a roadside bomb in Iraq, a Guard official said Thursday.

Sgt. 1st Class Michael Ottolini, 45, died in the explosion Wednesday as he was driving out of his base at Camp Anaconda, a sprawling U.S. military base about 50 miles north of Baghdad, family and friends said.

Described as a hard-working family man who loved serving his country, Ottolini was a member of the National Guard's 579th Engineer Battalion, headquartered in Santa Rosa.

Ottolini, who had served on a homeland security detail in Utah, came home earlier this year and almost immediately volunteered to go to Iraq with about 90 soldiers from a 579th company in Petaluma that left Sonoma County in March.

"The National Guard was his passion," said Rod McClintock, a lifelong friend who grew up with Ottolini in Guerneville.

"Mike was a great man," said McClintock's son, Jason McClintock, who drove hay trucks with Ottolini. "Very proud of his country and ready to die for his country."

Ottolini's wife, Sharon, and his children, Darrell and Stephanie, both in their late 20s, were in seclusion Thursday, friends said.

The Ottolinis were married while they were in high school, and Michael Ottolini went to work as a teenager at Noonan's Garage in Guerneville, Rod McClintock said.

Ottolini joined the 579th Engineer Battalion in 1979, the same unit in which his father, Dan Ottolini, had served.

"He was one of the most beloved guys in the unit," said a member of the 579th, who asked not to be identified.

Ottolini is the third man from Sonoma County to die in Iraq since the U.S.-led invasion began in March 2003.

Marine Lance Cpl. Patrick O'Day, 20, of Santa Rosa died March 25, 2003, when his tank overturned in the Euphrates River near Nasiriyah in the early days of the war in Iraq.

Former Army Ranger Sgt. Christian F. Kilpatrick, 25, was killed May 1 in an ambush near Tikrit while working as a civilian contractor on a security detail.

Born in Penngrove and schooled in San Rafael, Novato and Sacramento, Kilpatrick had served four years with the Rangers in Afghanistan and Iraq.

O'Day and Kilpatrick were buried with full military honors in Sonoma County.

Ottolini's body remained Thursday in Iraq, and funeral arrangements were pending, a National Guard official said.

Two other members of the 579th Engineer Battalion, neither from Sonoma County, were killed in June when their patrol was ambushed near Balad.

They were the first combat casualties in the history of the battalion, which was formed in 1946.

As a guardsman, Ottolini studied hard for tests to gain promotions, friends said. He participated in a road-building mission in Panama years ago and had helped flood-stricken residents of Guerneville, his hometown.

"He definitely loved what he did," Jason McClintock said.

Rod McClintock said he introduced Ottolini to hay truck driving years ago, and it became his life's work. Ottolini initially made long hauls for hay to Idaho, Utah and Colorado and coped with truck breakdowns on remote highways, McClintock said.

"Once you've hauled hay it's in your blood," he said.

For the past 10 years, Ottolini had driven a Peterbilt 18-wheeler for Southside Hay Co. in Cotati, said Nick Illia, father of the company's owner.

His hauls were mostly to the Sacramento Valley, enabling Ottolini to get home by the end of a day.

Rod McClintock said he was "devastated" by his friend's death. "It brings everything to a personal level," he said.

Just before Ottolini left for Iraq, he told Jason McClintock, "Right or wrong, I'm still going over there."

Since the war began, 1,155 U.S. troops have died in Iraq, including 877 in combat, according to the Associated Press. California has 137 war casualties, the most of any state. The figures do not include Ottolini's death.