Kaers were built underground, as Horrors have trouble passing through living Earth. They were also protected by powerful magical wards. Some kaers survived the centuries-long Scourge, many however have fallen to the Horrors (a guesstimate 50% rate of failure may be applicable). Some kaers were breached by powerful Horrors (either physically or Astrally) from the outside, others were penetrated by Horrors before they were sealed; and their occupants subject to a most disturbing and horrifying demise. Some were destroyed when their ecosystems failed.