ORLANDO, Fla. (AP) - A gunman opened fire Friday in the offices of an engineering firm where he was let go more than two years ago, killing one person and injuring five others.

Jason Rodriguez, 40, surrendered to police about three hours later, after officers saw him through the window of his mother's home and asked him to come outside, Orlando Police Chief Val Demings said.

She said investigators did not know why Rodriguez targeted the engineering firm where he once worked.

However, a television reporter who was present as police walked Rodriguez into a police station asked him why he went on an alleged shooting spree and Rodriguez responded "they left me to rot." He did not specify who "they" were.

He did not specify who "they" were and there was a lot of background noise at the time Rodriguez answered. He did not make any other statements.

"This is a tragedy no doubt about it, especially on the heels of the tragedy in Fort Hood that is on our minds," Chief Demings said. "I'm just glad we don't have any more fatalities or any more injuries than we currently have."

People streamed out of the 16-story Legion Place office building around lunchtime and some told local television stations they had barricaded themselves inside their offices while the gunman was on the loose.

Mike Bernof, a spokesman for Reynolds Smith & Hill, the transportation engineering consulting firm where Rodriguez was an engineer, told CNN Rodriguez was released in June 2007 for performance issues. He could not say what those issues were. The firm performs transportation engineering work for the Florida Department of Transportation.

Gerry Gilgo, who works on the floor where the shooting occurred, told The Associated Press she was meeting a co-worker at the elevators for lunch.

"She yelled, 'There are gunshots! There are gunshots! Get back in your office,"' Gilgo said.

Will Halpern, an attorney on the building's 17th floor, was among the last group to be evacuated. He said the lobby was filled with about 20 officers in SWAT gear, carrying assault weapons, ready to search.

Interstate 4 was closed in both directions through downtown and nearby schools were locked down until the gunman was caught.

Rows of ambulances lined up outside the building as police snipers took up positions around the building and officers on foot and horseback searched the area.

(Copyright 2009 by The Associated Press. All Rights Reserved.)