Paris in Peril

Paris Hilton is "teetering on the brink."

Law enforcement sources have told TMZ that Hilton has been crying a lot, praying and extremely withdrawn.

Hilton is in the medical ward at Twin Towers, an L.A. County jail facility. She is in a room by herself with a glass door. For her protection, a sergeant guards the door at all times.

We're told Hilton hasn't eaten or slept since she arrived yesterday.

Sources have described her condition today as "fragile" and "despondent." One source called her "a train wreck" while another said she is "sullen and withdrawn."

We've learned her shrink, Dr. Charles Sophy, spent more than two hours with her this morning. Hilton's family can't visit today. In the medical ward, families can only visit on Sundays and Tuesdays.