Sarah Connor, who wished to stop Judgment Day before it happens, used files from the T-800 from the future to track down Miles at his home in the hope of killing him. Sarah initially tried to kill Miles with a CAR-15 sniper rifle, but Miles evaded the bullet when he was momentarily distracted by his son, Danny Dyson. Sarah opened fire again, but Miles took cover behind his desk, where the bullets, though critically damaging his computer and prototype, failed to reach him. With her rifle empty, Sarah ran into the house with a .45cal side-arm and began shooting at Miles at close-range, eventually hitting him in the shoulder and cornering him, his wife, and son. Miles asked Sarah what she wanted from him, and Sarah, enraged, vocally blamed him for everything that was to transpire without any full explanation, only prompting Miles to utter an innocent "...What?" to which Sarah broke down emotionally and could not bring herself to kill Miles in front of his wife and children when he was not even responsible for anything yet. Sarah's son John and the T-800 arrived at that moment in response to the attack, and terminator cut off the outer-flesh of his arm and hand exposing his cybernetic arm and hand. Miles was shocked to discover it was identical to the one in the laboratory and realized the connection to him at this point.
Sarah, John and the terminator, after Miles's wound was partially-healed and the shock of the attack had died down, explained Skynet's future and its true effects on humanity to Miles and his wife. Miles was convinced to quit Cyberdyne and said he would destroy his prototype unit, computers, disk drives, optical drives, files, notes and any other contents of his office. However, the terminator made him realize that as long as the laboratory and technological artifacts at Cyberdyne were intact, Skynet could still exist as others would use his research and continue to create Skynet. Miles then planned to go with the Connors and the Terminator to the Cyberdyne building and destroy the research, and also sent his family into hiding. Before leaving, Tarissa agreed with Miles that Skynet had to be destroyed above all else and bid him good luck.
Miles initially hoped to enter the building undeterred and destroy the contents of the lab without opposition. But the guard refused due to the late hour of the night and lack of proper paper-work which needed to be done for access. Instead, the group forced their way in at gun-point and, after Miles helped John gather the advanced technological artifacts of the original Terminator from the high-security lab, began preparing to destroy the entire laboratory itself with a massive polydichloric euthimal bomb. Los Angeles police arrived at the scene. The T-800 used a minigun and shot at all of them, destroying their cars and terrorizing them. Just as the bomb was ready, multiple SWAT teams arrived in response to the break in and one unit stormed the building. The team opened fire and Miles's body was riddled with bullet-wounds before he took cover.
Knowing his injuries were fatal, Miles bid the others to escape and stayed behind to trigger the bombs' remote, which would be flipped by a large piece of the Neural Net Processor model in Miles's hand; which would drop when he died. The SWAT team realized this when they cornered him at gunpoint as he lay on the ground, and promptly panicked and ran away. Miles succumbed to his injuries with a heartfelt and slow death noted by shallowed labored breathing and died a few seconds later. His lifeless hand dropped the model on the trigger, destroying the lab and a sizable portion of Cyberdyne Headquarters.
All of this was in the middle of the Assassination of John Connor (1st attempt). Even though the building was destroyed, in Terminator 3, Judgment Day still happens, and this event only delayed it. In the Sarah Connor Chronicles, The Turk is responsible for Judgment Day and John and Sarah Connor pursue it.
In Terminator: Dark Fate, the termination of Skynet was successful and the AI was erased from existence. However, three years later John Connor was assassinated by another T-800 sent back by Skynet before its destruction known as Carl. Though Skynet was gone, it would be replaced by the AI Legion.
- "*" Denotes, in the Terminator: The Sarah Connor Chronicles timeline, these events occur in the year 1997 instead of 1995.