‘Blindsided’! Dina Lohan in Tears Over Lindsay’s Real-Life Nightmare

In part one of Entertainment Tonight's exclusive interview with Lindsay Lohan's mother Dina, the emotional mom tells our Samantha Harris about crying "hysterically" with her daughter after Lindsay was sentenced to 90 days in jail.

"You know, we were just both hysterically crying," admits an emotional Dina. "We were so blindsided by this."

Dina says she and Lindsay believed her court appearance on Tuesday was a mere formality – and that she was in compliance with court-ordered terms of her probation for a 2007 DUI arrest, including attending substance abuse education classes.