[CathyRyan]

If it was just one floor. Why not the other floors as well is well? If it were environmental. Water pipes leading to that one floor? The staff would have been explosed more than a guest would if it were air. Curious.

[Domestic Church]

We don't know if any of the cleaning crew have been affected. What are they odds they all got it from the elevator buttons on that floor (But no one else contacted it from the elevator buttons on the interior of the elevator?...AIRBORNE.)

[RLC]

Maybe the cleaning crew for that floor brought it in.

[Domestic Church]

"The staff would have been explosed more than a guest would if it were air. Curious."

Perhaps the air in the hallway isn't circulated and the heat/CA in each room has its own contained air flow unit with an external vent option. Many motel chains have a similar set up. That way if the heating/cooling breaks down it doesn't affect all the rooms.