I posted a panel from this story the other day, and it inspired an...interesting discussion. Here's the context behind it. It comes from Amazing Spider-Man #365. Tom DeFalco plotted it, Stan Lee wrote the script and John Romita Sr. illustrated it.
Mary Jane thinks about the day Captain Stacy died, in which during a fight between Doctor Octopus and Spider-Man, a chimney fell over and Stacy was crushed saving a little boy from being hit.