Planes simultaneously taking off on intersecting runways halted at Chicago's Midway Airport

Two passenger jets simultaneously began to take off on intersecting runways at Chicago's Midway International Airport, forcing controllers to order one to halt to avoid a collision.

The Federal Aviation Administration says it is investigating Tuesday night's incident in which a Southwest Airlines flight to Tulsa, Oklahoma, had been cleared for takeoff.

An air traffic controller saw a Delta Air Lines flight to Atlanta beginning to take off on an intersecting runway without proper clearance as the Southwest flight began to speed down its runway.

The controller ordered the Delta crew to stop immediately. The Southwest plane also stopped.

Each plane stopped about 2,000 feet from the intersection.

Delta said it was cooperating with the investigation, but offered no other details. Southwest said its plane later continued to Tulsa.