The collision occurred on the night of August 15 (local time), but the information only appeared on August 17. Both airlines have confirmed this information to CBS News.
Delta Airlines' Boeing 737 aircraft crashed into the rear of an American Airlines Boeing 757 waiting to take off to Dublin. Delta aircraft are ordered to move. The American Airlines captain described it as a "horrific collision".
Delta's Boeing 737 returned to the gate and all passengers had to get off the plane - the airline said in a statement.
Passengers on the American Airlines flight were transferred to another flight to depart for Dublin. The damage to the plane is being assessed.
The incident comes weeks after a near-disaster in aviation at San Francisco airport, when an Air Canada plane landed on the runway where four other aircraft were waiting to take off.
The Canada Traffic Safety Committee said the Canadian plane was less than 8 meters away from one on the runway and 30 meters away from the other two.