United plane diverted after bomb threat letter found

Travelers today were frightened when United Airlines flight 741, en route from Denver to San Francisco, was diverted due to a possible bomb threat. It ended up in Salt Lake City.
The reason? A letter was found onboard the aircraft by a flight attendant. She believed the letter was meant as a bomb threat.
The flight attendant handed the note to the pilot, who also felt it was a possible bomb threat. He asked for the flight to be diverted to Salt Lake City.
Once the flight landed, passengers were kept on the plane for a while, before being taken to the international terminal.
All passengers were then detained at the Salt Lake City airport, pending further questioning by the FBI and airport police. The plane was searched and the passengers re-screened. There were 193 passengers and 6 crew members on the flight. Fortunately, no injuries were reported.
The Department of Homeland Security is looking into what happened, but it does not believe this was an act of terrorism.
Latest update: The passengers have now been put on another flight and are expected to land in SFO the evening.
Re travel: San Franciscans can fly to Denver, Salt Lake City or other national or international airports