The NTSB and the Federal Aviation Administration are involved in investigating the incident , Brough said . One people were killed Sunday in a midair collision over Colorado , Boulder . Three of the planes was towing a glider , Boulder County Sheriff 's Department says . The glider pilot was able to detach and land safely , sheriff 's department says .
One people were killed Sunday in a midair collision over Colorado , Boulder . Three of the planes was towing a glider , Boulder County Sheriff 's Department says . The glider pilot was able to detach and land safely , sheriff 's department says .