10 Worst Things That Ever Happened To Spider-Man
3. Accidentally Murdering Gwen Stacy - The Amazing Spider-man #121-122
Anyone familiar with the timeline of Spider-Man knows that there are precisely two events that scarred Peter so badly that they defined him. The first is - naturally - Uncle Ben's murder, and the second is the death of Gwen Stacy.
It would have been bad enough were Gwen to have merely died at the hands of one of Spider-Man's enemies, but the comic manages to make a scenario that is somehow even worse. After seeing Gwen be dropped off a building by the Green Goblin, Spider-man rushes to her aid, launching a web that appears to save her, until the next panel shows her clearly broken neck.
While the incident isn't Spider-Man's fault, many fans have argued that this technically means he killed her, as the whiplash from her fall suddenly completely stopping is what ended her life. Peter himself has expressed serious grief and guilt over similar worries, which is especially awful when you think about the fact that there wasn't anything else he could do but try and save her that way - leaving him wondering whether letting her die or killing her is actively worse.