It took Nantucket firefighters about two and a half hours early Saturday morning to extinguish a blaze that started in a pile of debris in the construction and demolition waste building at the Madaket landfill.

No one was injured and no equipment damaged in the fire, which was reported via alarm at about 4 a.m., fire chief Steve Murphy said.

“The duty crew was already attending to an ambulance call and fire alarm (at the time),” Murphy said. “Deputy chief Robert Bates responded, finding heavy smoke in the C&D building with sprinkler-system activation. After clearing the previous fire alarm the duty crew responded with the engine, as well as off-duty personnel responding from home. Crews extinguished the remaining fire with the help of machinery on site used to pull the pile apart to reach the buried fire.”

Firefighters were on the scene until approximately 6:30 a.m. The fire is believed to be accidental in origin, Murphy said. The three-headed sprinkler system inside the building activated and worked as intended to hold the fire in check until their crew could respond, he added.

“No equipment was damaged and the building appeared to sustain only minor damage,” Murphy said. “We are very grateful the sprinkler system did its job.”

Landfill operations will not be impacted by the fire.