A man inquiring about a job at a Gowanus factory on Monday shot two workers and barricaded himself in the building before killing himself, authorities said.
The two victims were hospitalized with critical wounds, said New York Fire Department spokesman Daniel Glover.
The incident began shortly after 11 a.m. when the 54-year old gunman, whose name was not released, shot two people and barricaded himself inside the steel fabrication plant C&A Iron Works in Brooklyn, said New York Police Department spokesman Detective Marc Nell.
He then shot himself, police said.
Local media reported the man had asked for a job and started shooting after he was turned down.
Dmitry Tabakin, a plant worker, told the New York Daily News that the gunman seemed calm and was quiet before he started firing.
"I saw him put the gun to the worker's chest and shoot," Tabakin said.