Judge gives Trump administration two days to unfreeze funds for US foreign aid ; Two small planes collided in midair over one of the runways on the outskirts of Tucson last week.

DALLAS — Today, in 1920, the world's first air traffic control (ATC) tower opened. The new facility was located at London's then-main airport, Croydon.

Tens of thousands of planes take off, land and perform touch-and-goes at the Marana Regional Airport in southern Arizona every year. Without an air traffic control tower, it's a calculated dance that requires communication by pilots.