There's many fictional and nonfictional stories about passerby detecting dead bodies inside buildings and such by an "overwhelming stench of decay" or something equivalent, usually even through thick walls or from separate houses. But the total mass of a human is somewhat less than the mass in an averaged-sized dumpster which gets its own smells of decay, and I usually don't detect a dumpster unless I get extremely close and/or it was left open. I probably couldn't guess there was a dumpster in the adjacent apartment or anything remotely like some of these stories.
Do people (knowingly or subconsciously) exaggerate the sensation after the fact because it's a human body and it's creepy? Or is there some scientific reason that dead bodies have a smell that pervades a whole area more than normal rotting organic material?