Wake Forest, N.C. — Police are investigating the stabbing death of a 23-year-old man at a Wake Forest apartment complex.

Dorian Kwame Cunningham died at WakeMed Wednesday evening after the stabbing, sometime around 6 p.m. at Glen Royal Mills Apartments, 876 N. Main St., Apt. 218, authorities said Thursday.

Investigators initially classified his death as accidental but now they say they are treating it as suspicious.

Police did not say why, but according to a 911 call released Thursday afternoon, the caller said that Cunningham's girlfriend told her that he tripped over a box and fell onto a knife that was sticking out of it.

Cunningham reportedly lived at the apartment with his girlfriend and her daughter, and neighbors said they heard arguing coming from the home Wednesday evening.

Bill Crabtree, a spokesman for the Town of Wake Forest, said that within the past year, police responded 12 times to domestic-related calls at the address.

At least one was to check on the welfare of someone at the address, Crabtree said. Another had to do with a disturbance, and a third related to Wednesday night's stabbing, Crabtree said.

He could not say speak of any of the other instances, saying not every police call results in a police report.

Cunningham was a former correctional officer at Polk Correctional Institution in Butner but resigned in July 2012, according to a spokesman with the North Carolina Department of Public Safety.