A 40-year-old firefighter from the west metro died overnight after a rigorous training session.

Capt. Jeff Vollmer, a 12-year veteran of the Mayer Fire Department, died early Tuesday at his home, the department announced Wednesday.

Vollmer’s death came in the line of duty, the department said, as he had participated in training the previous night. On Thursday, Gov. Mark Dayton ordered flags flown at half-staff to honor Vollmer.

Eden Prairie Chief George Esbensen, a board member with a statewide foundation that is responsible for the Fallen Firefighter Memorial at the State Capitol, said Vollmer’s training Monday was “physically challenging” and was followed by apparent cardiac arrest suffered about 4 a.m.

The Mayer Fire Department scheduled training that night to refresh its personnel’s emergency medical service skills, “getting people out of tight spaces, moving people up and down stairs,” said Esbensen.

Mayer Fire Chief Rod Maetzold attended his department’s nearly 1 hour and 45 minutes of training, which included carrying people and putting them on stretchers. Maetzold said Vollmer “went through it just fine.”

It is because Vollmer’s training at the Community Center was hands-on, and more than sitting in a class-like environment, that his death is being considered as coming in the line of duty, Esbensen said.

A final confirmation of that classification by Minnesota and U.S. agencies would free up survivor benefits for Vollmer’s heirs.

Flags at the National Fallen Firefighter Memorial in Emmitsburg, Md., have been lowered in Vollmer’s honor.

The Mayer Fire Department is a volunteer agency and compensates its firefighters for training, duties, standing watch and special events.

A memorial service for Vollmer is scheduled for Saturday at 11 a.m. at Mayer Lutheran High School. Visitation will be at Freshwater Community Church in Waconia on Friday from 5 to 8 p.m. and again on Saturday starting at 10 a.m. at the high school.

Vollmer will receive a solemn send-off from hundreds of fellow firefighters in Minnesota and other states, who are being directed to arrive at a staging area near the high school with their department vehicles no later than two hours before the service begins. Afterward, a procession of firefighter vehicles will escort Vollmer roughly 7½ miles from the high school to the Johnson Funeral Home in Waconia.

Dayton also has ordered flags flown at half-staff on Saturday to honor Vollmer.

Vollmer is survived by his wife of 11 years, Emily; daughters Anika, 9, and Kennedi, 7; parents Art and Arlene Vollmer, of Ortonville; and sister Jaclyn Ekern, of Sartell, Minn.