IIRC, the chain had to be put there as a substitute because whenever you took the hose the stairs would go up and thus hinder you to get down and away with your hose trophy. Oh, about the chain: this was used as a replacement for the fire hose (item ID 35) so Jill could obtain exactly that 35 hose part that was installed inside the red box above the stairs (which in the retail versions is empty from the beginning, because there’s only the full hose item 3F).
Resiyoyoyo From the Resident Evil 1 2 3 Modding Forum Also Found Out what the chain item could have been in place of here is a quote : Thanks to Helegad & Max for the contributions! RE 3 had a much quieter development than Resident Evil 2, but we can still find a few unseens in the game, like some beta items and a room that was never used in the final game. Resident Evil 3: Nemesis, released in Japan as Biohazard 3: Last Escape, is a survival horror developed and published by Capcom for the original Playstation.