After the investigation of the accessible wreckage was completed , United Airlines requested that the remaining debris be destroyed by the military . Attempts were made to accomplish this , but despite the use of explosives , artillery fire and — according to most sources — napalm bombs dropped from aircraft , complete obliteration of the wreckage was not possible . One source , a 2007 book about the Rocky Mountain Rescue Group , contradicts the assertion that military jets bombed the site with napalm ; instead , the book states that the cliff face was mined with explosives that were detonated in the spring of 1956 , and the event was tightly controlled and not publicized . Regardless of the disposal method , small fragments of flight 409 's airframe and parts of the engines still exist in the area surrounding the crash site . Prior to the loss of United 409 , the deadliest scheduled airline accident in U.S. history was the June 1950 disappearance of Northwest Orient Airlines Flight 2501 over Lake Michigan , when 58 died . The 66 lives lost on Medicine Bow Peak remained the highest death toll on a scheduled airline flight in the U.S. for less than a year . In June 1956 two airliners , a Super Constellation and a DC-7 , collided over the Grand Canyon , killing 128 people . Flight 409 's crash , and other crashes and mid-air collisions in the United States that occurred over the next several years , convinced the U.S. Congress to improve airline safety procedures , and to increase civil aviation radar coverage
Northwest Orient Airlines Flight 2501
Northwest Orient Airlines Flight 2501
United Airlines Flight 409