Big Jim. He is killed by a creatur named Doomsday
On the last page of several comics prior to Superman: the Man of Steel #18, a gloved fist was shown battering a steel wall, with the phrase "Doomsday is coming!" in a caption. In that issue, Superman fights the Underworlders while a hulking figure in a green suit rampages through a pastoral field.
The story continues in Justice League of America #69, where the Justice League (Guy Gardner, Blue Beetle, Booster Gold, Maxima, Fire, Ice, and Bloodwynd) respond to a call from a smashed big rig, and follow the trail of destruction until the unknown creature destroys Blue Beetle's aircraft. The League attempts to stop him, but he systematically takes them apart, finishing by punching Booster Gold into the stratosphere, where Superman catches him, and Booster declares "It's like Doomsday is here!"
In Superman #74, the Man of Steel arrives on the scene, having cut an interview with Cat Grant short in JLA #69, and he and the able-bodied League members follow the threat to the home of a single mother and her two children, where their battle with "Doomsday" destroys the house. The League attacks Doomsday with all their energy-projection powers, but do not harm Doomsday. Doomsday takes them out, causes the house to explode into flames, and then leaps away. Superman follows, having to ignore the son's cries for help if he must stop Doomsday.
In The Adventures of Superman #497, Superman throws Doomsday to the bottom of a lake, slowing him down long enough for Superman to go back and save the mother and her baby daughter. Doomsday escapes from the silty lake bed, he and Superman tear up a city street, and then Maxima involves herself. Lois Lane pulls Jimmy Olsen from his "Turtle Boy" show taping to cover the battle while Lex Luthor Jr. dissuades Supergirl from joining the fight. The fight goes into a gas station, where Maxima rips a light post from the ground; the sparks from the wiring meet the leaking gasoline and blow the station up. Guardian arrives after Doomsday leaves, finding Superman and Maxima, and offers his aid.
In Superman in Action Comics #684, Superman follows Doomsday's trail of destruction over a few states starting from the mid-west to a LexMart, where Doomsday sees a commercial for "War Bash 9000." It distracts him long enough for Superman to attack. The battle continues across a few more states heading towards Metropolis. The Daily Planet helicopter arrives, and Lex Jr. convinces Supergirl that she's needed in Metropolis while Superman is fighting. Doomsday sees a road sign for Metropolis
connects it to the War Bash commercial, but Superman throws him in the opposite direction, where he lands on the mountain housing the Cadmus Project. They brawl throughout Habitat, bringing most of it down. When Guardian arrives, Doomsday knocks them down and leaps toward Metropolis.
In Superman: the Man of Steel #19, their brawl sends Doomsday into Underworld, where Doomsday ruptures a gas main, and then an electrical main, which levels Newtown. At one point he kocks Doomsday out and then tries to help some firemen put out a building that is on fire. A fireman looks at him and tells him to sit and breath from an oxygen tank. Superman tries to ignore him and the Fireman orders him to sit down and get some oxygen. At this point Doomsday gets up again and the battle is on again. Supergirl goes to aid Superman, but a single punch from Doomsday knocks her to the ground, her form destabilized and reverted to her purple Matrix form. Professor Hamilton and Bibbo shoot Doomsday with a laser cannon, but it does not harm him. Metropolis SCU open fire on Doomsday, but again, he is not harmed. Superman returns to the fight. By this time Superman is a big wound.
In Superman #75, Superman and Doomsday lay into each other with everything they have. Superman looks inside and realizes that if he is going to put Doomsday down, he needs to give it all he has, which isn't much left. Superman figures out how to hurt Doomsday - his bony protrusions are extensions of his skeleton - Doomsday stands up, and they battle again. He looks at Lois with a look that tells her that he knows he is not going to come out of this alive. Just as Lois figures out what the look Superman just gave her means, both he and Doomsday deliver one final blow to each other that is so powerful that the glass from buildings for blocks shatter from the impact. It knocks everyone to the ground. When Lois stands up she sees Doomsday down, but so is Superman, and the battle has made a huge swath acroos many states, and alot of damage to the eastern half of the United States. Whole towns in the path of the battle have been torn apart. Metropolis is in ruin and half of the people in the town have pretty much been killed or burried in the rubble of the city's ruin. Lois runs to Superman and places him on her lap. He asks her if he killed Doomsday. She tells him he did. He tells her he has always loved her, and then dies in her arms.
The above comic is the one that he dies, and I believe it is the one that came out on October 10, 1992.
The paramedics on the scene try to revive him, but it is no use.
They take him to the nearest hospital where Professor Hamilton, who had successfully saved Superman a year or two prior from a kryptonite bullet, is brought in to help. But an hour later he emerges and tells the world that Superman was pronounced dead 10 minutes earlier. The entire world mourns. The reporter who is the equivalent of Dan rather cries while giving the news.
Funeral for a Friend and the Reign of the Supermen
The following funeral featured many of Superman's fellow heroes and friends, including most of the Justice League of America. At one point in the procession following Superman's castket as it is being taken by a horse through the ruin of downtown Metropolis, a terrorist tries to take advantage the situation and is about to throw a bomb at of all the Presidents of all the worlds Countrie's, who are all walking in one part of the procession. Just as he is about to, Batman, who makes a rare apearance in the daylight, grabs the guy and is about to beat the "F" out of him. He tells the guy "If this were my town you would be dead. But this isn't my town and I have to play by my dead friends rules." He ties the guy up and leaves him hanging from a pole I believe. A mausoleum was built in Metropolis in his honor. Furthermore, stories after the funeral often dealt with the emotions felt by the general public as well as specific characters entwined within Superman's world, including Lois Lane (Who tries to maintain her composure until she gets home to the downtown condo that she and Clark call home and looses it), Clark Kent's parents (Who don't go to the funeral as they need to maintain the illusion that Clark Kent and Superman are two different people, and are forced to watch their sons funeral from Smallville. Pa suffers a heart attack a day or two after from the stress and dies), and even a number of supervillains (Lobo is pissed that Superman was killed as he wanted to be the one to kill him). The Cadmus Project stole Superman's body, but Supergirl helped recover it.
"The Death of Superman" brought in millions of readers to DC Comics, despite the entirety of the story being intertwined through numerous different comic series, including Action Comics, Superman, Superman: The Man of Steel, and Adventures of Superman, among others. The cover of Superman #75 became a famous image: Superman's tattered cape wrapped around a pole, marking a makeshift grave.
Because of Superman's place as an American icon, his death became a multimedia event, covered by newspapers and televised reports. Certain prints of Superman #75 contained a black armband with the familiar "S" symbol adorning it. Many comics fans publicly wore the armband immediately following Superman's death, including, perhaps most famously, Jay Leno.