A man shot and killed a security guard before killing himself at a federal building in New York City on Friday.

The gunman walked into a building at 201 Varick Street in lower Manhattan around 5:05 p.m. on Friday and shot the guard with a handgun. He then walked to a nearby elevator and fatally shot himself in the head, reported Reuters.

James O'Neill, chief of department of the New York City Police Department, identified the alleged shooter as Kevin Downing, 68, a veteran and former employee with the Bureau of Labor Statistics who lived in Fort Lee, N.J., a community just on the other side of the George Washington Bridge that connects Manhattan and New Jersey. Officials still do not know if Downing ever worked at the office in the Varick Street building or at some other location, according  to USA Today.

The building, which has offices of a Department of Veterans Affairs, U.S. Post Office, The National Urban Security Technology Laboratory and an Immigration Court, among others, was placed on lockdown and evacuated following the shooting.

The wounded security guard, Idrisa Cammara, was taken to Lennox Hill Hospital in cardiac arrest and was pronounced dead on arrival, according to a hospital spokeswoman, The Los Angeles Times reported.

"It's obviously a tragedy when anyone is killed like this in the line of duty," Department of Homeland Security Secretary Jeh Johnson said while speaking to reporters. 

"We are shocked and horrified at this terrible news and send our deepest condolences to Officer Camarra's family. Security officers around the city and country serve on the front line each and every day to keep us safe and secure. We are heartbroken that one of our own has fallen. We hope some of our questions in the face of this terrible tragedy will be answered. For now, we are keeping Officer Camarra's family and loved ones in our thoughts and prayers", said Service Employees International Union Local 32BJ, which represented Camarra, CBS News reported.