The death of Captain James T. Kirk (William Shatner) in Star Trek Generations received a mixed response, at best, but Trekkers likely would have been up in arms if his demise, as originally conceived, made it into the film. Although Star Trek Generations was the first film starring the cast of Star Trek: The Next Generation, Kirk's death made the crossover movie an event and it was the last time Shatner canonically portrayed his iconic Star Trek hero.
In Star Trek Generations' theatrical cut, Kirk joined Captain Jean-Luc Picard's (Patrick Stewart) mission to stop Dr. Tolian Soran from destroying a star and the planet Veridian III. Soran needed the star's explosion to change the course of a space ribbon called the Nexus so the El-Aurian scientist could return to its otherworldly dimension. As Kirk fought Soran, Picard tried to disable the doctor's star-crushing missile. Kirk was killed when he fell from Soran's collapsing scaffolding and was crushed by twisted metal after he retrieved the madman's control PADD. Meanwhile, Picard enabled the missile's docking clamp so that it exploded in place when Soran tried to launch it, killing the villain. But it was too late for Jean-Luc to save Jim Kirk, and the original Captain of the Enterprise died after his final heroic act.
Star Trek Generation's climactic action sequence with Kirk, Picard, and Soran was actually the result of multiple reshoots. In the scripted ending, Soran murders Kirk by shooting him in the back. In the original orders of events, the pair had a grueling fistfight and Soran and was knocked unconscious. Kirk then retrieved the control PADD from Soran's belt, unaware the doctor had regained consciousness. Armed with a phaser he hid in his boot, Soran blasts Kirk. Too late to save Jim, Picard gets revenge by shooting Soran with his own phaser, killing the El-Aurian. Picard promises the mortally wounded Kirk he'll be fine and that Jean-Luc will find a way to contact his starship, but Kirk dies, assuring Picard that, "It's the least I can do for the Captain of the Enterprise."
The original showdown and death of Kirk written by Star Trek Generation's screenwriters, Ronald D. Moore and Brannon Braga, was more straightforwardly violent. Soran shooting Kirk in the back is cowardly, and Picard's retaliation in equal measure was also out of character for the cerebral Captain, who took on more action hero traits in the sequel First Contact. Kirk's demise was also more clearly aimed at passing the torch as Captain of the Enterprise to Picard. Worse, Kirk dies without uttering his now famous last words: "It was... fun! Oh my!"
Shatner wisely felt his character's death was lacking something crucial on the page and added Kirk saying, "Oh my!" so that the Captain faced the unknown with a moving mix of fear and wonder as he breathed his last breath. While Kirk's death in the sequel was still an inglorious end to one of Star Trek's greatest heroes, the original ending that was filmed robbed Kirk's last moments of proper dramatic weight. While fans didn't love how Kirk died in Star Trek Generations, the original version would have been a disaster if it had been the ending. Therefore, it's understandable why Generations' producers decided to 'fix' the finale, although they didn't address the fundamental issues with how and why Kirk dies.
According to his 1994 memoir, Star Trek Movie Memories, Shatner was called back for two reshoots in order to craft the ending fans ultimately saw. Star Trek Generations' finale cut both Soran shooting Kirk in the back and Picard murdering Soran. The villain dies by an explosion because Picard tricked him while Kirk lost his life performing a heroic act, which is still underwhelming but isn't quite as ruthless. Amusingly, Malcolm McDowell is probably the one who most missed Kirk's original death since he took delight in taunting Shatner on Star Trek Generations' set about being the chosen one to shoot Captain Kirk in the back.