A New Orleans police officer shot and killed a man Saturday morning in the Lower 9th Ward after the man had left much of his block in disarray.

The shooting happened near Caffin Avenue and Chartres Street about 9:30 a.m.

An NOPD homicide detective who was investigating an unrelated case in the neighborhood shot the man, department spokesman Tyler Gamble said.

The detective, who has not been identified, was flagged down by someone who said a man had been driving erratically down the street. The detective, who was in an unmarked police vehicle but was wearing his NOPD uniform, caught up with the man and a physical altercation followed, Gamble said.

The situation escalated to the point where the officer shot the man, who died at the scene about 10:15 a.m. The officer was not injured.

Police Superintendent Michael Harrison said the officer was defending himself and felt he had to draw his weapon and fire.

Mayor Mitch Landrieu promised a “full and thorough investigation” of the incident.

Gamble said the man who was killed lived about a block away from the shooting and had been involved in an argument with his wife preceding the incident. At some point, he left his house and got in his pickup, crashing through a wooden fence as he exited the driveway.

He hit a parked car across the street, drove away and hit at least one more parked car before his truck came to a rest in a driveway about a block away, Gamble said.

Neighbors said the man also hit several houses with his silver truck.

What led to the altercation with the officer is under investigation, Gamble said.

Officer-involved shootings must be reviewed by the NOPD’s Force Investigation Team, a five-officer unit within the Public Integrity Bureau.

Gamble said authorities are investigating whether the man who was killed had a weapon. No gun was recovered at the scene.

The officer involved has been reassigned to desk duty pending the outcome of the investigation, which is standard procedure in the NOPD.

“It’s pretty evident just how dangerous a situation it was out there,” Gamble said, noting a block-long trail of damage that was left in the man’s wake.