SEABROOK — Friends and family of Massachusetts National Guard Maj. Mark Fitzgerald, of Seabrook, are mourning his Saturday morning death at the Veterans Administration Hospital in West Roxbury, Mass. He was 42.

Fitzgerald was featured in the Hampton Union in December when he surprised his 9-year-old daughter, Samantha, at Sacred Heart School in Hampton with his return for the holidays following an eight-month tour of duty in Afghanistan

On Monday, while at the home of Fitzgerald's wife, Cynthia, Army Reserve Capt. Mark Aldrich of Amesbury, Mass. talked about his friend of more than 12 years.

"He was my best friend, since 1998," Aldrich said of Fitzgerald.

Aldrich spoke of the disease, ulcerative colitis, that plagued and eventually claimed Fitzgerald's life.

"In 2005, he was in Iraq," Aldrich said. "He was visiting a local police chief and ate some food.

"Two days later he became really sick and was med-evacuated to Germany and then to Walter Reed," Aldrich said.

Aldrich said Fitzgerald spent three weeks at Walter Reed Army Medical Center in Washington D.C. While he did make a recovery from that attack, Fitzgerald's disease was chronic, Aldrich said.

"For all of us who knew him, we always worried about him," Aldrich said, adding Fitzgerald had experienced five or six bouts with ulcerative colitis over the past five years.

"He was at my house two weeks ago," Aldrich said. "I talked to him Friday, and he said he was doing fine, doing better," Aldrich said.

"You're talking about a great American," Aldrich recalled of his friend. "He was a Bronze Star recipient for service in Afghanistan ... He mentored the highest ranking police chief, a two-star general, in the Kabul City Police Command."

Aldrich said Fitzgerald had served in the military for more than 20 years. His service included two overseas deployments, the first in 2004 to 2005 to Iraq, and in 2010, when he left in April and made his surprise return home in December.

"He was committed to the military, and he was a Field Artillery Battery commander at the 101st Field Artillery Battalion in Danvers, Mass. from 2007 to 2009," Aldrich said.

Fitzgerald was called up right after Sept. 11, 2001, and ran a mission down in Cape Cod doing base security for three years before going to Iraq in 2004.

He had worked as a project manager at Sylvania until he left for Afghanistan last April, Fitzgerald said.

At Sacred Heart School, Interim Principal Maureen Cocchiaro spoke about Fitzgerald's sudden death at such a young age.

"It was a shock to us as a community," Cocchiaro said Monday.

"This morning, the faculty met and prayed together as a faith community, over the intercom, for the family and for Mr. Fitzgerald," Cocchiaro said.

"The children are making cards of sympathy and regret," Cocchiaro said. "It's very sad when this happens to someone so young."

Students in Grades 4 to 8 are welcome to attend Fitzgerald's funeral, Cocchiaro said.

Aldrich said arrangements are being handled by Remick and Gendron Funeral Home in Hampton.