The cat's 'sixth sense'...?

According to this news article, this cat at a Providence, RI nursing home is able to predict when someone is about to die. The doctors who work there are amazed because after years of medical experience and training, they have been wrong more often than not.

The article states that the cat somehow knows when someone is about to die, and goes and sits in their room, curls up on their bed, and waits.

Do you actually believe that the cat is able to detect it on its own, without following behaviour patterns of visitors and staff? Is there something that is released in the air by someone who is dying and the cat is able to detect those smells or chemicals?

I'm not sure how much of this is based on the cat observing and mimicking patterns of the staff, and how much of this is based on the cat actually able to detect the death of someone on it's own, independent of others' actions.