What signs did Randy see at the medical arts building that made him know something was wrong?

From the text:

There were reddish brown stains on the sidewalk and the green concrete steps. The glass in the front door was shattered and the door itself swung open. The waiting room was ominously empty. There was no one at the reception desk. Randy possessed a country dweller's keen sense of smell. Now he smelled many alarming odors-disinfectant, ether, spilled drugs, spilled blood, stale urine.