How many people have died in the air force?

Several thousand, surely. Count all the aircraft accidents since the Air Force was formed in 1947, and the combat losses in Vietnam, plus combat losses in Bosnia, Afghanistan and Iraq, plus common hazards like traffic accidents, and you can accumulate quite a total in 64 years.

Which is still a pretty low number, for as many people have been in the USAF, and for something as inherently hazardous as aerial combat and working on, in and around big jets.