his book The Physics of Superheroes, states that in the real world, the whiplash effect would have killed her. The comic book Civil War: Casualties of War: Captain America/Iron Man (2007) concurred that the proximate cause of death was the sudden stop during a high-speed fall. An issue of Peter Parker: Spider-Man revisits the issue, and further confirms Gwen died of a broken neck due to the use of the webbing. For some time, however, fans speculated that the shock of the fall itself caused Gwen Stacy's death, due to the Green Goblin telling Spider-Man in The Amazing Spider-Man #121, "Romantic idiot! She was dead before your webbing reached her! A fall from that height would kill anyone — before they struck the ground!" In the 1987 edition of The Official Handbook of the Marvel Universe, Gwen's death is attributed to the fall, not to Spider-Man's webbing. In the fourth issue of Marvels, it was reported that she died from the shock of the fall, however Phil, a photographer and witness, is unsure about exactly what kills her. Replays Several subsequent issues have echoed Gwen's death when others fell from great heights during Spider-Man's battles. On most occasions, he saves them by jumping after them and working with their momentum, rather than trying to stop them with his webbing (as he did in the What If? where he saves Gwen), most notably when he jumped off the same bridge to save Gwen's daughter, Sarah Stacy, around seven years after her death; due to accelerated aging caused by her Goblin-enhanced mutated body chemistry - Sarah's father being Norman Osborn after an artificial mixing of genes from Gwen and Norman to create the twins), Sarah looks exactly like her mother. In another storyline, the Green Goblin once again replays the scenario, this time with Spider-Man's wife Mary Jane Watson-Parker. As with Gwen, Mary Jane plummets toward her death (this time from the recoil from her gun when she shoots at the Green Goblin). Learning from his previous error, Spider-Man uses multiple weblines and catches every major joint, saving Mary Jane from suffering the same whiplash effect that killed Gwen. A similar event occurs when Spider-Man saves Anna Maria—the girlfriend of Otto Octavius during a time when he was in Spider-Man's body—when Green Goblin uses her as a hostage and throws her off a building after learning that his true enemy has returned,