Dispatchers received multiple calls just before 7:30 a.m. reporting the fire. Firefighters from several crews responded, including some who were off duty, according to the department.

The property owner was not on site when the fire began but arrived within the hour and used heavy machinery to break apart the pile so crews could reach the flames, the department said. No injuries were reported, and officials said no further hazards remained after the fire was extinguished.

In a Facebook post, the Abington Fire Department offered a scientific explanation for the unusual blaze, noting that heavy rain can trigger internal heat within large organic piles.

“At risk of sounding like Bill Nye the Science Guy…the heavy rain creates the internal heat reaction in the pile that ultimately creates the fire,” the department wrote. “If you think of the science of what happens in a composter for your garden, this phenomenon is occurring on a much larger level in this instance.”

Mulch and compost fires are a known hazard at landscaping and recycling facilities, where moisture and microbial activity can generate intense heat deep inside large piles. Such fires can smolder for extended periods and are difficult to fully extinguish without breaking apart the material, as the property owner's machinery allowed crews to do Sunday.

The fire department did not estimate a damage cost. The cause remains classified as a spontaneous heat reaction, officials said.