By mid-morning local time police had arrested a suspect in the exclusive Tantalus-Makiki Heights above the Hawaiian capital.
The gunman, named as 40-year-old Byron Uyesugi, entered the building on North Nimitz Highway, to the east of downtown Honolulu, shortly after 8am and opened fire during a meeting in a conference room.
Last night it was unclear whether he was still employed by the company at the time of the shooting
According to reports, he appeared calm and deliberate, selecting certain people, ranging in age from 33 to 58, and shooting them with his 9mm pistol and leaving everyone else unscathed. It was not immediately clear if the gunman spoke during the attack.
Dale Ajifu, a technician who was downstairs in the warehouse, said he heard the sounds of someone loading and unloading a firearm. "It wasn't a single shot. I think I might have seen the guy they're talking about," he said.
After the attack, the gunman climbed into a green company van and sped off into the morning rush-hour traffic. Just under two hours later, shots were heard at the nearby Dole Cannery building in Iwilei, but it was not known if the two events were related.
Police hurriedly evacuated a second Xerox office complex in central Honolulu as the chase continued, with Swat teams moving in
Meanwhile, police, paramedics, counsellors and bypassers milled about the scene of the shootings, reacting with consternation to the highly unusual outburst of violence in what is usually a peaceful island capital.
"It's a shock for all of us. We have such a safe community with almost no violent crime," Honolulu's mayor Jeremy Harris said.
"To have someone snap like this and murder seven people is just absolutely appalling."
Co-workers said Mr Uesugi had spent 10 years working in the building in Xerox's technical services division.
One colleague told local reporters he had seemed like "a nice, calm, cool guy". Police checks, however, revealed that he had 17 firearms registered in his name. Several officers were dispatched to Mr Uesugi's home in the Nuuanu neighbourhood in case he should appear there.
The building was cordoned off and eyewitnesses were kept from public view. One official, however, described the scene inside as "grisly". "Paramedics arrived at the scene and found seven males who were deceased from gunshot wounds," Robin McColloch of the Honolulu Emergency Medical Services said. He confirmed there were no living wounded.
The Xerox company, based in Stanford, Connecticut, issued a statement describing the shooting as a "tragic event". "Our foremost concern is for the safety and security of our employees and for the comfort of the families of the victims,'' the statement read.
This was the latest in a number of workplace shootings in recent months.
In July, a frustrated daytrader in Atlanta killed 12 people including his own family and customers at two different brokerage firms.
A week later, an office worker in Pelham, Alabama opened fire on his colleagues, killing three.
And six weeks ago, a deranged loner in Fort Worth, Texas, stormed into a baptist church in the middle of an evening prayer service and opened fire, killing seven people before turning his gun on himself.
President Bill Clinton has urged Congress to tighten federal gun control laws. He has also appealed to the film and video industry to tone down its violent output.
THE YEAR OF THE SHOOTINGS
16 September: Larry Gene Ashbrook, 47, from Fort Worth, Texas, opens fire on Wedgwood Baptist Church, killing seven people before shooting himself.
14 September: 42-year-old Dung Trinh is charged with opening fire at a hospital in Anaheim, California, killing three employees.
10 August: Buford Furrow from Washington state opens fire on children and teachers at a Jewish community centre in Los Angeles, injuring five, and kills a post office worker.
29 July: Mark Barton, an Internet trader, kills his family and shoots 12 people in Atlanta brokerages.
2-4 July: White supremacist Benjamin Smith, 21, goes on a weekend killing spree in the Midwest, selecting blacks, Jews and Asians in the Chicago area before taking his life.
20 May: T J Solomon, a 15-year-old student at Heritage High School in Atlanta, is accused of firing 14 shots from a rifle and a Magnum handgun, wounding six fellow students.
20 April: Eric Harris and Dylan Klebold use firearms and explosives to attack Columbine High School, Denver, killing 12 students and a teacher before killing themselves.
15 April: A gunman walks into the Family History Library in downtown Salt Lake City, killing two people and injuring four others before being gunned down.
6 October 1998: Joseph Neale, a disgruntled former employee of the city of Riverside, 60 miles east of Los Angeles, opens fire at city hall, injuring the mayor and four others before being overcome by security.May 1998: Kip Kinkel, 16, of Thurston High School in Springfield, Oregon, kills his parents then opens fire in the school cafeteria, killing two and injuring 20.
March 1998: Two teenage boys open fire on their classmates at a school in Arkansas, killing four pupils and a teacher.