Air traffic controllers were forced to use their personal cell phones to reroute hundreds of flights Tuesday after the Federal Aviation Administration’s Memphis Center lost radar and telephone service for more than two hours, snarling air traffic in the middle of the nation.

The malfunction, which occurred inside a telephone company’s switching office, made it impossible for air controllers at FAA’s Memphis Center to communicate normally with adjoining centers to hand off control of flights, Bergen said.

In addition, three of nine long-range radar systems were lost, causing the FAA to temporarily ground traffic within a 250-mile radius of the center, affecting flights in seven states, Bergen said.

At least Homeland Security wasn’t affected.