The Trans-Allegheny Lunatic Asylum , constructed between 1858 and 1881 is the largest hand cut stone building in North America. It was built to house 250 souls, but by the 1950's reached its peak inhabitants of 2400 souls in an overcrowded facility leading to very poor and unsanitary conditions. Changes in the treatment of the mentally ill, and increased deterioration of the building lead to its closing in 1994. There has been a plethora of evidence supporting paranormal hauntings at this facility, including "The Creeper" that resides on the top two floors showing itself as a black mist type creature, and has been heard scurring across the building's lengthy floors with a crab like sound.