A laid-off designer of women's accessories gunned down a former co-worker outside New York's Empire State Building before being killed by police in a rush hour shoot-out that wounded nine others.
None of the nine injured in last night's horrific, but brief shooting outside the iconic skyscraper risked dying, Police Commissioner Ray Kelly told a news conference.
The FBI quickly ruled out terrorism, a constant worry for New York's authorities.
Kelly identified the gunman as Jeffrey Johnson, a "disgruntled former worker" from a women's apparel business called Hazan Imports. His age was originally given as 53 but later corrected to 58.
"Johnson had been employed for six years at Hazan Imports as a designer of women's accessories. During a downsizing at the company about a year ago Johnson was laid off," Kelly said.
At about 9:00 am local time, just when the streets around the Empire State Building were filling with office workers and tourists, Johnson went to his former workplace and had an argument with an employee identified by US media as vice president of sales Steven Ercolino.
"Johnson produced a pistol and fired at close range, striking his 41-year-old victim in the head," Kelly said.
Kelly said the man used a .45 caliber handgun with a magazine capacity of eight rounds and fired three shots.
The shooter put his gun in a bag and tried to flee but was confronted by two police officers who had been alerted by a nearby construction worker, Mayor Michael Bloomberg told the news conference.
"The perpetrator clearly turned his gun on the police and tried to shoot them," Bloomberg said. "The cops returned fire, killing him."
It was unclear whether the gunman had time to fire at the police and some of the gunshot wounds to bystanders may have been caused by stray police bullets, the mayor said. "Some may have been shot accidentally."
This was only the latest in a string of high-profile shootings, including the massacre in a Colorado cinema and a Sikh temple.
"How long are we going to ignore America's gun crisis?" asked the Violence Policy Center, a gun control lobby. "It is long past time to regulate the out-of-control gun industry that makes these horrendous public shootings possible."
Bloomberg, one of the most outspoken politicians in the country on gun control, said New York remained the country's safest big city but added: "We are not immune to the national problem of gun violence."
Streets around the Empire State Building were closed as police flooded the area. Television helicopters hovered overhead, filming the aftermath, including the body of the suspect covered in a white sheet.
Police had no shortage of witnesses in the bustling neighbourhood.
"I was scared, in shock, literally shaking. It was just by chance I missed it," witness Rebecca Fox said. "I saw a woman covered with blood. Another woman was being taken to an ambulance."
Fox said she had also seen the gunman, who appeared to be of middle age and was lying on the ground.
"There was blood on the ground," she said.
Another witness said she heard shots ring out just as she arrived at her office, where she works in the personnel department.
"I was inside the building. He shot the manager outside and then ran to Fifth Avenue," Maria Almodovar Ramos said.
She said the shooting spooked her "because I work in human resources and when you let certain people go you don't know how the individual will react."
Police secured the area almost immediately and it was quickly apparent that only one shooter was involved.
The FBI also said shortly afterwards that there was "no nexus to terrorism."
Footage from news helicopters showed police inspecting the shooter's body under the north side of the Empire State Building. Officers were also seen marking about a dozen spots with evidence markers, many of them probably ammunition casings.
The tower is one of the city's icons on a par with the Statue of Liberty and the Brooklyn Bridge.
In 1997, six people were wounded and one killed in a shooting rampage on the skyscraper's observation deck before the gunman turned the gun on himself.