New York City Police say the fatal shooting of an unarmed man in Brooklyn by a rookie cop was an accident.

The victim, Akai Gurley, was shot and killed by offer Peter Liang, who was 18-months on the job, as Gurley and his girlfriend entered a dimly-lit stairwell in the Pink Houses apartment complex, The New York Times reported.

Gurley was rushed to Brookdale Hospital but he did not make it.

Police are currently investigating the shooting, the latest in a string of police-related deaths of unarmed men. In the meantime, NYPD Commissioner William Bratton said initial evidence suggests the shooting was "an unfortunate accident."

Gurley, 28, was a "total innocent" who "was not engaging in any activity other than trying to walk down the stairway," Bratton said, WABC reported.

The officer involved has since been placed on modified duty and stripped of his gun and badge.

Police say Liang and his partner were patrolling the building in Brooklyn's East New York around midnight as Gurley and his girlfriend were leaving the building after visiting a friend. The couple first tried taking the elevator but decided to take the stairs because it was taking too long, The NY Times reported.

Both officers were in the eighth-floor stairwell with their flashlights drawn. Police said Liang also had his weapon drawn.  As they descended the stairs, Gurley and his girlfriend entered the stairwell from the seventh floor door.

For unknown reasons, Gurley discharged his weapon, striking Gurley in the chest and knocking him down two flights of stairs, The NY Times reported.

New York City Mayor Bill de Blasio expressed his heartfelt condolences and also said Gurley's death appears accidental.

"This is a tragedy...A life was lost. My heart goes out to the family," the mayor said, WABC reported.

"We don't know enough now, but it appears to have been an accident," he continued. "We are going to do a full investigation and learn what it tells us going forward."

Gurley's death comes as racial tensions are boiling over in Ferguson, Missouri, where an unarmed black teenager was killed by a white officer following an altercation in August. Any minute now, a grand jury is expected to decide if Ferguson officer Darren Wilson is to be charged with 18-year-old Michael Brown's death.

Another grand jury is also underway on Staten Island, New York, in connection to the chokehold death of Eric Garner, also black, who died after several officers wrestled him to the ground during an arrest attempt in July.