WATERVILLE — Call fire Capt. Mike Folsom remained in critical condition Saturday at a Portland hospital after suffering a serious medical event Thursday that led to cardiac arrest and a single-vehicle crash, according to fire chief Shawn Esler.

Esler said in a letter to the community on Friday that Folsom had been called to the fire department while on personal vacation at 7 a.m. Thursday to help repair a municipal fire alarm system and then was asked to help with another project.

Folsom left the station to get additional tools to complete the repair and at 11:42 a.m., police and fire officials were called to a single-vehicle accident on Silver Street where they found Folsom unresponsive, Esler’s letter says.

“Firefighters, paramedics and department’s physician provided on-scene advanced life support.”

Folsom was taken to Thayer Center for Health on North Street and then flown by LifeFlight of Maine to Maine Medical Center in Portland and was in critical condition Friday but was showing improvements, according to Esler.

Contacted Saturday morning, Esler said Folsom’s condition remains the same as it was when he wrote the letter, though he declined to comment further out of consideration for Folsom’s family.

Any information will be released at the discretion of his family, Elser said, adding that he would not be discussing it publicly.

Folsom, a well-known and respected city employee, started at the fire department as a call firefighter in 1985 and has worked full time as a carpenter at the city’s public works department since 1999.

“Nearly every major project, repair or improvement around Waterville has directly involved Mike Folsom,” Esler said in his letter. “He is the go-to person among the city departments and he simply gets the job done. He is well-known as a kind, caring individual who would give you the shirt off his back or lend you a helping hand. Hew asks for nothing in return, and he never expects any recognition for his accomplishments.”

The fire department, public works and city finance office are collecting donations  and those wanting to donate may visit the finance office at City Hall at 1 Common St., according to Esler.