An elderly man was stabbed to death inside his Manhattan apartment by his roommate nearly half his age after an argument turned deadly early Monday morning, authorities and law enforcement sources said.

Alon Riabichev, 45, is facing murder charges in the slaying of Lev Vayner, 80, after he allegedly knifed the victim in the abdomen and neck at their 37 Overlook Terrace residence in Hudson Heights around 3:15 a.m., police said.

Exterior of the apartment building located at 37 Overlook Terrace in Manhattan, New York.The victim and suspect were roommates, sources said. Kyle Mazza/Shutterstock

Riabichev called 911 following the fatal encounter and was arrested at the scene, sources said, adding that a knife was found at the scene.

Medical examiner pushing a stretcher with a body bag on a New York City sidewalk.The victim was pronounced dead at the scene. Kyle Mazza/Shutterstock

Vayner died while still in the building, according to first responders.

The victim and accused killer got into a dispute leading up to the stabbing, sources said, though it was not immediately clear what the argument was over.

Riabichev was charged with murder and criminal possession of a weapon hours later, the NYPD said.Â