Major spoilers ahead for Avengers: Endgame. If you have any die-hard Tony Stark/Iron Man/Robert Downey Jr. fans in your life, you might want to call them and make sure they're okay. That's not just a general prescription, though some might say that stanning the nearly insufferable, self-important Tony Stark might be reason alone to need a friendly chat. But this time it's actually vital that you offer support to the biggest Stark fans in your life because Iron Man's fate in Endgame, will cause even the least sentimental MCU fans — those who are Tony Stark-level dispassionate — to shed a few tears. As you could probably infer from that description, Iron Man dies in Endgame.
Tony's death is foreshadowed in Endgame when he nearly dies in space, stuck there with Nebula and not enough food. The oxygen in the ship starts to run out and Tony leaves a resigned goodbye hologram message for fiancé Pepper Potts (Gwyneth Paltrow), not sure that she'll ever even receive it. That isn't the real end for Iron Man, thanks to Captain Marvel, but it hints that Tony Stark has pressed his luck enough, and he's not as invincible as he may like to believe.
That Tony Stark dies in Endgame not only proves that the tech genius isn't infallible, but that he's also more human than he'd ever wanted to admit.
After the five year time jump, Tony's new life looks better than that of any of the other Avengers. Because Pepper survived the deathly Infinity Stones snap, she and Tony finally get to settle down and they even have a daughter together who they name Morgan (like in Tony's dream!). Tony begrudgingly rejoins the Avengers to help them pull off Scott's time-traveling plan to retrieve the stones from the past, but he warns Captain America (Chris Evans) that he will choose his family over the Avengers.
In the end, Tony does the opposite of what he'd said he'd do. He sacrifices himself on the battlefield when going head-to-head against Thanos. While Captain Marvel succeeds in stealing the Infinity Gauntlet off of his wrist, Thanos tricks her by taking all of the stones out of it. When he gets the Gauntlet again, Thanos replaces the stones, and then Iron Man pulls the same trick by taking all of the Infinity Stones. Thanos snaps, but nothing happens without the all-consuming power of the Stones. "I told you, I am inevitable," Thanos says, before he realizes his mistake. Tony quickly turns his hand into his own Gauntlet and, just before snapping his own fingers, he says, "I am Iron Man."
The line that Tony delivers before snapping his fingers echoes the announcement he made during the press conference at the end of the first MCU movie, from 2008. The stones' power kills Iron Man, which isn't a surprise considering that the Hulk (Mark Ruffalo) even falters after snapping his fingers, and he's used to dealing with radiation.
Tony Stark dies a hero after all, but it's not necessarily because he's an actual superhero, but because he's a human who cares about others, especially now that he has a daughter. By turning back on his word that he wouldn't save the Avengers if it risked his life, Tony Stark proves that he really does have a heart, which the Arc Reactor that Pepper framed in the first Iron Man joked about 11 years ago. Tony's Endgame death drives home the MCU's longstanding message that the Avengers' greatest asset is usually their humanity over anything else.