Thanks nrets for the initial post and flyflyfly for providing an edited version.
One aspect of the situation which is lost in the edited version is the speed with which the fire appears to have taken hold. Less than a minute before declaring an Emergency the pilot told ATC that the parachutists were ready to jump and he made no reference to a problem. To demonstrate my point, this transmission is included in the audio file I'm attaching here with all the subsequent transmissions in real time.