SPOILER WARNING: This article contains major spoilers for "The End," the Season 5 finale of Agents of S.H.I.E.L.D.
Marvel's Agents of S.H.I.E.L.D. just suffered a major casualty. In "The End," the Season 5 finale, Leo Fitz was killed when a ceiling collapsed on him. Fortunately for Fitz's friends and fans alike, this may not be the end of the beloved S.H.I.E.L.D. scientist. Thanks to the season's time travel plot, a past version of him still exists in deep space.
As Graviton wreaked havoc on Chicago in his quest for gravitonium, S.H.I.E.L.D. arrived to evacuate civilians and clear the buildings impacted by the crash landing of his alien warship. Mack took Fitz and May up into one of the skyscrapers, where they discovered Robin Hinton and a breach in the ship's hull. Realizing Robin's mother Polly was still inside the ship, Mack went off to rescue her while May stayed behind with Robin.
At that moment, Fitz realized they were playing into the world-ending scenario they'd tried so desperately to avoid. "May, neither of them make it," he said slowly. In an effort to prevent Mack's death, they pursued him and saved him from two Marauder soldiers. As they exited the ship and walked back into the building, though, Graviton and Daisy's fight created a tremor that caused the concrete ceiling to collapse right on top of Fitz.
Mack and May immediately dug Fitz out. Underneath the rubble, they discovered him shaken, but alive. "I hope you saved some energy, because my leg's bent. I think he's broken," he told them. "You'll have to carry me out." As they moved a large piece of concrete out of the way, they realized the damage was much worse than that. A large metal sheet had pierced through his torso.
At this, Mack realized Fitz was dying, so he knelt down beside his friend. "Relax, buddy. Just breathe," he said, taking his hand. "Just breathe. I'm going to stay with you. We'll find a way out of this."
In shock, Fitz told them to get Polly out of the ship, that she was in danger. May assured him she was safe. "Hey, man. You got her out! You did good, Turbo!" Mack said. "You did really good."
"Hey, Mack. I think my leg's broken," Fitz whispered. "You've been through worse," Mack replied, choking back tears. Fitz then laid his head back and passed away.