Batman's parents were shot and killed by a criminal in an alley. It was a random act of violence that had a profound impact on Bruce Wayne's life and led him to become Batman.
In the comics, Batman's parents were killed when they were walking home one night. A criminal approached them, demanded their valuables, and then shot them both. This tragic event led Bruce to vow to fight crime and seek justice.
In some fanfictions, James Potter's parents could die in a wizarding battle against dark forces. Maybe they were targeted by some dark wizards who wanted to eliminate the Potter family's influence in the wizarding world.
In a particular fanfic, James Potter's parents might die in an accident. For example, they could be traveling using some form of wizarding transportation, like a flying car or a magical carriage, and something goes wrong. A malfunction in the magic that powers the vehicle could lead to a crash that takes their lives.
Peter Parker's parents passed away in a plane crash that was part of a complex and shadowy plot. The details of their deaths have been explored in various comic storylines, adding depth to Peter's backstory.