 The crew members were using the time to run through their checklist again , when a momentary increase in AC Bus 2 voltage occurred . Nine seconds later ( at 6 : 31 : 04 @.@ 7 ) , one of the astronauts ( some listeners and laboratory analysis indicate Grissom ) exclaimed " Hey ! " or " Fire ! " ; this was followed by two seconds of scuffling sounds through Grissom 's open microphone . This was immediately followed at 6 : 31 : 06 @.@ 2 ( 23 : 31 : 06 @.@ 2 GMT ) by someone ( believed by most listeners , and supported by laboratory analysis , to be Chaffee ) saying , " [ I 've , or We 've ] got a fire in the cockpit . " After 6 @.@ 8 seconds of silence , a second , badly garbled transmission occurred , interpreted by various listeners as : 
