A bomb threat at the state Capitol shut down and emptied the building for nearly two hours Wednesday as authorities responded to an early morning cell phone call warning of death and destruction.

"We got a phone call from a very agitated male caller who said there would be a lot of damage and a lot of lives lost," Utah Highway Patrol spokesman Sgt. Wade Breur said.

The call, which was received at 7:28 a.m. by Valley Emergency Communications Center dispatch, led to the building's evacuation of about 650 people about 30 minutes later.

UHP spokesman Lt. Bruce Riches, who oversees Capitol security, said the FBI and the state's office of Homeland Security are joining the investigation to trace the origin of the call.

Riches also said the caller told dispatchers the device was set to detonate between 8 and 8:30 but didn't specify morning or evening.

More than 40 officers from three state agencies, some dressed in camouflage and armed, and four bomb-sniffing dogs performed a 467-room search of the Capitol.

Although no explosive device was found, some lawmakers were irritated by the time lost from the final 10 days of the 2004 session.

"This is not a positive thing for the Legislature or for the people of Utah," said Senate President Al Mansell, R-Sandy. "The real damage done is that there just won't be enough time to hear all the bills that were scheduled to be heard in committee meetings."

The House finally convened around 11 a.m., when Speaker Marty Stephens, R-Farr West, opened the session by saying: "We will not be cowed by anonymous threats; the work of the people will go on."

At an afternoon news conference, he said that he was disappointed by the lost time, which will be made up with extended floor sessions and earlier committee meetings this week.

Both leaders said security would be visibly increased during the final two weeks of the session, although they did not provide any details. The one thing they did not expect to do was restrict people from carrying legally permitted concealed weapons, and they doubted that there would be metal detectors at the doors.

Riches said his office has four metal detectors that can be assembled and activated in less than 30 minutes and that discussions about installing them in the two chambers' temporary quarters for the next four years have been in the works.

"Security will be stepped up in those new buildings," he said. "We take this type of threat very seriously, because we don't know when it's a hoax and when it's not."

At any given time during the legislative session, between 1,000 and 2,000 people walk the Capitol's halls, making any threat against public safety impossible to ignore, Capitol Preservation Society executive director David Hart said.

"You have to realize you can create any barrier you want, but that just ups the ante," he said. "Sept. 11 plays into every threat that comes in, and we treat each one very seriously."

Though investigators wouldn't release any other details of the phone call, the man apparently passed a series of cues from a checklist each dispatcher is provided that deemed the threat credible, Riches said.

"There's a system in place that goes up the chain of command and determines what actions law enforcement will take," Division of Emergency Services and Homeland Security spokesman Derek Jensen said.

He also said the threat was the second in two years, the first one last Christmas before legislators convened for their annual 45-day session.

Police believe Wednesday's threat is unrelated to any of the number of bills introduced in the Capitol's chambers this session, Riches said, adding that the man could face prosecution under domestic terrorism penalties.

"We think the caller will get a kick out of what he did and tell other people, and I truly believe we'll get him," he said.

Gov. Olene Walker was meeting with Democratic leaders at the time of the disruption, which required the meeting to be moved to a secure location in the basement of the State Office Building, where Walker waited out the delay.

The governor was brought to the location — her first visit in the 12 years she's served in Utah's executive branch — at approximately 8:30 a.m. until the Capitol was declared safe two hours later, governor's spokeswoman Amanda Covington said.

Some legislators made the most of the downtime, meeting with colleagues, constituents and committee members in the nearby State Office Building.

"I spent the whole time meeting with people," said Sen. Patrice Arent, D-Salt Lake City, "but I hope that we do make up the time because it's very valuable for us to have it."

The governor expressed frustration at any additional delays to the lawmaking process but said the Capitol should remain open to the public.

"These sorts of things are an irritant," she said at a press conference. "This is something we take very seriously and it will be pursued, but we want to make the Capitol the people's building."

Contributing: Josh Loftin.

E-mail: abenson@desnews.com