Chicago (CBS) — Investigators at O’Hare International Airport are trying to figure out how two planes nearly collided Friday around noon.

Officials say the two passenger jets, one American Airlines and other other Envoy Air, took off from parallel runways at O’Hare around 12:20 p.m.

One pilot banked a hard left and the other a hard right to avoid a possible mid-air collision.

“Harrowing for passengers, clearly was a split-second decision, saved catastrophe,” said Joe Schwieterman, an aviation expert at DePaul University.

The Federal Aviation Administration, calling it a “possible loss of separation”, is investigating. But, a spokesperson says it appears the Envoy aircraft began a left turn instead of going straight as instructed.

An air traffic controller noticed and called for that plane to stop climbing and turn.

The FAA is still gathering information. An airline spokesperson said both American and Envoy Air are cooperating.

Nobody was injured.