Weld County was thrust into the media spotlight on the evening of November 1 , 1955 , when United Airlines Flight 629 , a Douglas DC-6B airliner flying from Denver to Portland , Oregon , exploded in midair and crashed , killing all 44 persons on board the plane and scattering bodies , wreckage and debris over a six-square-mile area of the county . The subsequent investigation of the accident revealed that Denver resident John Gilbert Graham had secretly placed a time bomb composed of 25 sticks of dynamite in a suitcase belonging to his mother , who was a passenger on the airplane . Graham was tried and convicted of the crime , and executed in 1957
United Airlines Flight 629
United Airlines Flight 629
Weld County, Colorado