DEMI MOORE's three daughters have been plunged into a nightmare by their mother's terrifying drug-and-booze collapse and emergency hospitalization, say sources.

"Demi's breakdown has triggered a family-wide crisis," revealed an insider.

"Their dad BRUCE WILLIS is battling to keep his children from following in their mom's footsteps."

Youngest daughter TALLULAH has become the biggest cause for concern. The 18-year-old rebel was busted for underage drinking last year and seems to be taking her mother's breakdown the hardest.

"Mom has made my life a living hell," she told a close source.

Tallulah, who's always been closer to her father than mom, argues a lot with Demi, according to the insider, who added: "She's mortified and depressed over her mom's current condition." Tallulah has been trying to "cope with her mom's substance abuse problems," said the close source. "She recently confessed to a friend, 'My life has become a living hell due to the drugging and drinking of one of my family members' — a direct reference to Demi.

Pick up this week's issue — on newsstands now — for more on Tallulah and how Demi's other daughters are coping.