“Our hearts are broken at the loss of our brother Det. Ben Campbell,” the Maine State Police wrote on Facebook. “Rest in Peace, brother. We have the watch.”
The deadly incident happened around 7:30 a.m. on Interstate 95 in Hampden, state police said in a separate post.
“The trooper was out of his vehicle at the site of disabled car along the Interstate and the other vehicle involved in the crash was a tractor trailer,” the post said.
Campbell was attending to the disabled vehicle when two wheels detached from a truck passing by, state police said, according to The Associated Press. One of those wheels hit Campbell, Maine State Police Chief John Cote said.
Campbell was transported to a hospital in Bangor, Maine where he passed away, according to state police.
The driver of the involved truck was identified as Scott Willett, who pulled over after the wheel became detached, Cote said.
Maine Gov. Janet Mills issued a statement on Twitter after the fatality, which said she ordered that U.S. and state of Maine flags be flown at half-staff across the state on Wednesday.
“On behalf of the people of Maine, I express our deepest and unwavering gratitude for Detective Campbell's service,” she wrote on Twitter. “Together let us keep his family, friends and loved ones, along with Maine’s entire law enforcement community, in our thoughts and prayers during this difficult time.”
The Associated Press contributed to this report.