BOUNTIFUL -- The South Davis Metro Fire Agency has announced the death of Fire Marshal Steve Cox, a 22-year firefighting veteran.
Agency Chief Jim Rampton called the death a "huge loss."
Officials say the death is the agency's first in the line of duty.
Cox, 55, died Sunday after becoming disoriented and complaining of shortness of breath Friday while performing a firefighter skills fitness test.
Cox became ill during an exercise at Fire Station 81, officials said. Fellow firefighters administered first aid and took him to Lakeview Hospital.
"Steve became unresponsive and was admitted to the ICU," stated an agency news release.
On Saturday, his condition worsened and his body organs started to shut down, states the release. He was taken by helicopter to University of Utah Medical Center.
Cox died about 3 p.m. Sunday.
"Doctors have no answers as to what happened," states the release. "An autopsy is being completed by the state medical examiner's office."
Farmington Fire Chief Guido Smith said for three months Cox also worked part-time as fire marshal for his city.
In that short time, Smith said, Cox made a significant contribution.
He said Cox was always willing to help and treated business owners as customers.
Cox was serving as chairman of the Davis County Fire Chiefs Association and led training of fire inspectors, Smith said.