Ben Reilly was impaled by the Green Goblin's glider in Spider-Man #75, and died shortly afterward. His body degenerated into nothingness, like a clone's, which led Spider-Man to conclude that he was the real Peter Parker after all.
If you're interested in the clone saga, check out
www.grayhavenmagazine.com. In the 'Columns' section you'll find a link to an ongoing series titled, 'Life of Reilly', which is an indepth review of the clone saga with insider information provided by former Marvel editor Glenn Greenberg. It is very much worth the reading. For example, it was revealed in the last column that the mastermind of the clone saga was not intended to be Norman Osborn