The two men and a woman lie unconscious on the seat and the ground below as pedestrians walk past them in Blackburn, Lancs.
Marketing boss Daniel Healey, 35, captured the pictures and video footage from his office window shortly after 2pm last Tuesday (Sept 12).
He said: "It's completely freaked me out, they look like the addicts are virtually dead.
"They are plaguing the streets and it's very harrowing and freaky to watch but members of the public just simply walk past and don't care.
"It's like the street is turning into zombie central from the footage and photos, it's disturbing."
Spice is a psychoactive drug which is a former legal high and designed to mimic the effects of cannabis.