From vacationing families to international business travelers, passengers at Salt Lake City International Airport downplayed any anxiety Monday about flying the day after the world learned of Osama bin Laden's death in a U.S.-led mission.

"Just another day," said Matthew Giddings, of Provo, seeing his in-laws off to Fort Hood, Texas.

Terror experts said Monday that bin Laden's death may temporarily decapitate al-Qaida, but the threat of terror attacks remains — and it could spike in coming days from individuals or small extremist groups inspired to take revenge.

"People who are angry at us will be more so," said Matthew Levitt, a counterterrorism and intelligence expert at the Washington Institute for Near East Studies. "They had attacks in the works last week, last month, today — and those things can still happen."

The U.S. Department of Homeland Security and FBI confirmed the retaliatory threat Sunday, issuing a bulletin to law enforcement officials across the nation. The warning said bin Laden's death could inspire extremists to speed up their plans for attacks and that threats could come from unidentified al-Qaida operatives in the country who could move forward with their own plots.

"Bin Laden's death may provide justification for radicalized individuals in the United States to rapidly mobilize for attacks here," the document stated.

Homeland Security Secretary Janet Napolitano said the government doesn't plan to raise the terror alert level in the United States.

But at the Salt Lake City airport, passengers seemed largely unconcerned about a possible heightened security risk.

Wearing a New York Yankees cap and chatting on his cellphone, Elias Campbell seemed surprised to be asked about it while he waited to retrieve his bag.

"I don't think I gave it a thought either way," Campbell said. Then, recalling his flight from Portland, Ore., Campbell said the Southwest Airlines crew made an effort to put passengers at ease.

"They were all speaking in hushed tones," he added. "It was nice."

Exiting the Delta Air Lines terminal, travelers said their flights were business as usual. So seemed the attitudes from the modest and orderly crowds snaking through security checkpoints.

"I guess we would have hoped they made the [bin Laden] announcement tomorrow, but there's nothing we could do," said Brian Officer, who was returning home to St. Paul, Minn., with his wife and 5-year-old son.

Officer said he briefly pondered changing his flight Sunday when printing his boarding passes at a hotel.

"I thought about it a little bit," he said. "But we have to get home."

Rosalyn Wik, who spent all day flying from Florida, with a stopover in Atlanta, said she never so much as flinched after catching the bin Laden headline early Monday.

"Is that naive?" she asked, rushing to baggage claim.

Airport spokeswoman Barbara Gann said "there are no procedural changes at all."

She said that airport security is heightened but the change wouldn't be visible to the public.

Two burly Department of Homeland Security inspectors, wearing black labeled jackets, could be seen pacing Terminal 1 and scanning the crowd from a centralized elevator.

That did little to faze Oregon native Bob Brunskill, who calmly trudged through line on his way to Bucharest, Romania, for business.

"It's actually one more problem eliminated in the world," said Brunskill, who never hesitated to fly Monday. "And I'm headed that way."

Asked if he ever thought he would see the demise of bin Laden, Brunskill paused, then offered his most demonstrative reaction — a wry smile.

"I was pleasantly shocked."

Salt Lake Tribune writer Derek Jensen and Associated Press writer Eileen Sullivan contributed to this report.