Partner and I were at a school on the far west side of our district by Hwy 99. We hear sirens but are at the back of the school and can't see anything. Then... the ROAR of a helicopter circling low over the school. Chopper came in for a landing on the school grounds to pick up an accident victim from a bad crash on the highway. Took them to Fresno to the regional trauma center I guess. Funny thing was that just an hour before, we were parked in the area that the chopper landed replacing a bad valve.