646th Radar Squadron

The 646th Aircraft Control and Warning Squadron was the operational USAF unit of Highlands Air Force Station. The unit operated the Texas Tower 4, an offshore radar annex from 1958 until it collapsed into the Atlantic Ocean on 15 January 1961, killing 28 people. The squadron was activated on 1 June 1948, and renamed to the 646th Radar Squadron (SAGE) on 1 October 1958.