Malfunction Of Fan Caused Quincy Sewage Plant Fire

QUINCY (CBS) -- Fire officials say a mechanical failure of a fan caused the fire at a Quincy sewage treatment plan on Monday.

An industrial fan's malfunction led to a release of a sulfur-based dust cloud, which exploded and sparked the fire at Massachusetts Water Resource Authority's Nut Island Headworks on Sea Avenue, according to a statement released Wednesday morning by the State Fire Marshal's Office.

Five workers were taken to a hospital after suffering smoke inhalation when a small explosion and fire started several stories underground inside the plant.

The fire was difficult to put out due to its location, fire officials say, and firefighters had to use "self-contained breathing apparatus' capable of longer than usual operational time."

Investigators had to wait until the air conditions were safe before entering the plant to determine the cause of the blaze.

The plant handles first-stage waste water treatment, and the workers were doing maintenance work on the air handling system used to de-odorize gases and air before release into the atmosphere, according to the statement.