The Amazing Spider-Man #090 (1970)
“And Death Shall Come!”
Writer: Stan Lee
Artist: Gil Kane
Captain George Stacy dies when a pile of bricks fall on him due to Doctor Octopus’ arms flailing around in a fight with Spider-Man. Spider-Man is largely blamed for Captain Stacy’s death. Before he dies, Stacy reveals to Spider-Man that he knows he’s also Peter Parker. Then asks Peter to take good care of Gwen.