U.S. government investigators say evidence shows a commuter plane was on the wrong runway when it crashed and burned Sunday killing 49 people.

The National Transportation Safety Board chief investigator Debbie Hersman says data from Comair flight 5191's records and evidence at the scene show the plane took off from a runway that was too short for aircraft of its size.

The Lexington, Kentucky, airport has two runways. One is 2,134 meters long and the other - not meant for commercial traffic - is only half that length. Investigators say it isn't immediately clear how the plane ended up on the shorter runway.

Authorities said the Atlanta-bound two engine Bombardier model CRJ-200 jet crashed and burned soon after takeoff from the airport with 47 passengers and a crew of three on board.

The sole survivor, the plane's first officer, is being treated at a Lexington hospital and is reported in critical condition.

Some information for this report was provided by  AP and Reuters.