BUTLER TWP — A 17-year-old boy died Tuesday of a suspected heroin-related overdose, authorities said.

Emergency crews were called about 7:40 a.m. after the boy’s grandfather found him unresponsive at their home in Butler Township’s Grandview section.

Township police declined to comment on evidence found at the scene, citing the ongoing investigation.

Butler County Deputy Coroner Larry Barr, who pronounced the boy dead at the scene, said he suspected an overdose.

An autopsy was performed Tuesday. Authorities said that a cause of death is pending results of toxicology tests.