An off-duty FBI agent fatally shot a man on a crowded Washington D.C. train platform during the evening rush Wednesday, police said.

The special agent and the man tussled with one another, falling eight feet off the platform inside the Metro Center Station around 6:20 p.m. before the agent fired several times at the man, killing him, DC police said during a press conference.

DC Executive Assistant Chief of Police Ashan Benedict said the man who was killed appeared to have started the altercation and that agent, who he described as a “veteran,” is believed to be the victim.

The man “assaulted” the agent and the pair got into a struggle. One grabbed the other and both tumbled over a wall to a lower walkway away from the tracks, Benedict said.

The brawl continued on the lower level until the off-duty agent took out his gun and shot the other man, he said.

It’s unclear if the man who was killed had a firearm. No gun was recovered by the time the press conference was held about two hours later.

The agent was taken to an area hospital for treatment of minor injuries.

The sound of gunfire echoing through the busy station created panic among commuters and suspended service along the Red Line.

Witnesses said they saw dozens of people sprinting out of the station and straphangers drop to the ground upon hearing shots, according to social media reports.

At least one train continued straight through the station without stopping, apparently after the conductor heard the shots.

“Really grateful for the quick reaction & thoughtful attention by our rail operator tonight whose response during tonight’s police involved shooting at @wmata Metro Center kept customers from potential danger,” Metro General Manager and CEO Randy Clarke tweeted.

DC police are leading the investigation into the shooting with the assistance of the FBI.