Case closed on unsolved D.B. Cooper airplane hijacking

The FBI is closing its active investigation into the airplane hijacker D.B. Cooper. The case has puzzled FBI investigators for the last 45 years, and is the country's oldest unsolved skyjacking.

The case started on Thanksgiving Eve in 1971 on a flight from Portland, Oregon to Seattle.

A man who called himself Dan Cooper told flight attendants he had a suitcase bomb. The crew met his demands for parachutes, $200,000 in cash, and to redirect the plane to Mexico. He leapt from the plane, possibly over southern Washington. Cooper was never seen again.

It drew international attention, and led the FBI to look into thousands of theories and tips as to his whereabouts.

FBI Seattle spokesperson Ayn Dietrich-Williams said people in her office have different theories about what happened.

Williams: "It seems like at some point everyone has touched this case to some degree. So there are a lot of people in this office who are happy to see resources going to higher priorities, but also disappointed that we couldn't solve it."

Some theories say Cooper died after the jump. For one, he was wearing only a business suit, jumping into cold weather and possibly freezing rain.

None of the bills he was given appeared to make it into circulation, except for $6,000 in cash that washed up near the Columbia River.

The FBI's Seattle office says it's closing the case now in order to focus on other investigations. Still, the bureau invites anyone with physical evidence in the case to turn it in.