Wasn't there myself but I've been following Waverly Hills closely for years and I'm genuinely curious what you experienced. Was it more of a physical sensation - pressure in the chest, temperature drop, that kind of thing - or something more psychological like a sudden dread or feeling watched?
The reason I ask is there's a pattern in BEK reports and certain hauntings where witnesses describe a very specific kind of "wrongness" before anything visual happens. Almost like your nervous system clocks something before your conscious mind does. I've had that twice here in Cornwall at locations with strong residual activity.
Also what floor were you on? The body chute and the 5th floor tend to produce very different types of reported experiences and I want to see if what you felt maps onto what others have reported from the same areas. The more specific you can be the better, even small details matter here.