Was Delta flight struck by July 4 fireworks in Chicago? Pilot says 'felt a big bang'

A Delta flight landing in Chicago on July 4th reported a startling 'big bang' as it was apparently struck by fireworks at a low altitude.

Air traffic control acknowledged multiple similar incidents, even warning another pilot of a 'war zone.' While the Delta flight landed safely with no injuries and no damage found, the FAA has launched an investigation into the dangerous close calls during the holiday celebrations. ...