The fire that completely destroyed NBA commentator Mike Breen's home last month was caused by a "careless disposal of staining material," officials tell TMZ Sports.
We broke the story ... the play-by-play man's Long Island house was engulfed by heavy flames at around 4 AM on Sept 25 -- and it was deemed a complete loss after the inferno was extinguished. Thankfully, no one was hurt or at the residence at the time of the fire.
After a thorough investigation, Nassau County Chief Fire Marshall Michael Uttaro tells us the blaze originated in the garage ... due to materials that had been improperly stacked in the space.
"The house was under construction," Uttaro said ... adding, "When all those materials are stored in a pile, they can combust causing a rapid fire."
Uttaro says fires like these have sadly become commonplace ... telling us "it happens often" -- but he said he's happy Breen and his family are safe.
Breen -- who's been an NBA announcer for 30 seasons and has become known for his "Bang!" call -- thanked everyone for their support during the Knicks' preseason game days after the incident.
"I didn't want to take anything away from the game, I just want to give a heartfelt thanks to so many people who offered kindness and support this past week after the fire at my family’s home on Long Island," the 61-year-old said. "Just a reminder for me of how many wonderful people are in my life."