More than one out of five Boston firefighters scheduled to work Memorial Day called in sick, prompting the fire commissioner to threaten disciplinary action and demand medical notes from each absent jake, the Herald has learned.

The massive no-show further embroils an embattled department already under fire for skyrocketing overtime costs and widespread disability abuses.

Firefighters scheduled to fill 122 day and evening shifts banged in sick that holiday Monday, compared to 69 on Memorial Day last year, said Fire Department spokesman Steve MacDonald. On average, about 34 firefighters are out sick each day, a figure that jumps to 66 on holidays.

MacDonald said the wholesale absences did not jeopardize public safety because many of the shifts were covered by overtime.

Fire Commissioner Roderick J. Fraser Jr. sent a general order to all firefighters yesterday vowing that anyone who cannot provide a doctor's note justifying a Memorial Day absence would receive a sick leave abuse warning and potentially face further discipline, MacDonald confirmed last night.

Fraser declined to comment.

The Fire Department has spent at least $18.6 million on overtime this fiscal year - more than $6 million over what they were projected and allotted to spend.

City Councilor Steve Murphy, chairman of the Ways and Means Committee, called the mass absence "alarming."

"It's too much of a coincidence," Murphy said. "It's one of the reasons the City Council will be taking a hard look at all of those numbers and expecting answers."

MacDonald said the total cost of overtime to cover the absent firefighters has not been calculated.

Boston Firefighters Local 718 is mired in a bitter contract dispute with the Menino administration and appears headed for arbitration. Several officials with knowledge of closed-door discussions said firefighters want more than the 14 percent raise offered by the city over the next four years in exchange for random drug and alcohol testing.

Meanwhile, the department faces a federal probe into pension abuse because the number of firefighters retiring with disability pension has skyrocketed over a five-year period from 49 percent of retirees in 2002 to 72 percent in 2007, according to the Boston Municipal Research Bureau.

Republished with permission of The Boston Herald.