SEATTLE (AP) _ A gunman opened fire today in a commercial building, killing one person and wounding three others. A search was under way for the attacker.

Police used search dogs in the hunt. Several schools in the area north of downtown Seattle were locked down while the hunt continued, KOMO-TV reported.

The shooting happened about 10:30 a.m. in Seattle's Wallingford neighborhood at an office building called the Northlake Shipyard building, police said.

``He walked in and started shooting. That's all we know,'' said Pam McCammon, a police spokeswoman.

The suspect was described as a man, possibly in his 30s, wearing a camouflage jacket and brown hat when he walked in a back door of a business and started shooting with a gun, police said.

McCammon said one person was killed, two were critically injured and a fourth person suffered lesser injuries. Earlier, police had said five people had been shot.

The injured were taken to Harborview Medical Center, where two men were in critical condition with gunshot wounds, and one was in less serious condition with a gunshot wound in the arm, hospital spokesman Larry Zalin said.

Jeannie Parr said she was about 6 feet from where the shootings took place.

``He came in calmly,'' she told Northwest Cable News. ``I didn't hear any sounds of a confrontation or argument. ... All I heard was gunshots.''

Scottie Pierce of Seattle Boat, across the street from where the shootings happened, said he was sending his employees home early.

``It's almost a surreal type situation, faced with what the nation went through in Hawaii yesterday,'' he told Northwest Cable News. ``I'm quite concerned that there's someone running around with a gun.''

Seven people were shot to death Tuesday at a Xerox Corp. building in Honolulu. The suspected gunman, a Xerox employee, fled after the slayings and surrendered hours later.