A longtime building supervisor at 432 Park Avenue South, a 16-story apartment building in Midtown, suffered a fatal heart attack yesterday afternoon, during a fight with a bike messenger that began in the building's lobby and spilled out onto the sidewalk.

According to the NYPD, officers responded to the apartment building shortly after noon yesterday, where they discovered 58-year-old Roger Balan of Long Island unconscious and unresponsive. He was pronounced dead upon arrival at Bellevue Hospital. The bike messenger, who police identified as 35-year-old Devon Givens of Williamsburg, had allegedly fled the scene by the time police arrived.

The Post reports that the men got into an argument in the building's elevator before moving out into the street, where witnesses said Givens threw the first punch. As the men hit each other, Balan reportedly slumped suddenly against a car and "grabbed his chest," prompting Givens to flee the scene. It is not clear what prompted the men's argument.

"I came around the corner and it was fast, no blood," a witness told DNAInfo. "It looked like he just got exhausted and passed out."

"The bike messenger jumped on his bike and rode off like he didn't want anything to do with it," another witness told the Daily News. Givens was reportedly arrested at his next delivery, around 3:30 p.m. at 60 Wall Street. He has since been charged with manslaughter.