ABC news reported Msgr. Patrick Chauvet, who was at the cathedral when the fire broke out about 6:20 p.m. Paris time on April 15, said the organ with its 8,000 pipes was, except for dust, left unscathed. Its origins date back to 1401; some pipes of the medieval period still exist today.
Have a listen to its magnificent sound. (Though after restoration, depending on the materials used, it will sound different.)
Note how long it takes for the sound to decay after Mr. Olivier Latry stops playing!