“Samantha was poking her,�? says the onlooker. “She didn't respond. She was totally passed out."

The two then headed to an unidentified residence where they both spent the night. Lohan entered the treatment facility the following morning.

Says a pal, “She’s a troubled girl. Maybe this will be her wake-up call, but at this point, we don’t know.�?

Lindsay was driving her black Mercedes convertible on Saturday when she
clipped the curb and hit bushes on Sunset Boulevard at 5.30am.
Los Angeles Police Lieutenant Mitch McCann - who is heading the
investigation - said the actress was not seriously injured but was taken to
Century City Doctors Hospital for treatment for minor chest injuries.
McCann also revealed a "usable amount" of cocaine was recovered from the
severely damaged vehicle during the investigation.

The 'Just My Luck' star - who had been partying at Les Deux nightclub before
moving on to a private bash and then the Skybar at the Mondrian hotel - was
charged with DUI at the hospital, and McCann said "additional charges may be
filed."

Lindsay completed a 30-day course at Los Angeles' Wonderland rehab facility
checking in on February 16, and also attended Alcoholics Anonymous meetings.

However, since leaving the facility the 'Georgia Rule' actress has been
accused of secretly drinking vodka from a water bottle when out partying.

Meanwhile, Lindsay's father has insisted she and her mother Dina should go
to rehab.
Michael - who has be estranged from Lindsay since he was jailed for DUI and
assault charges in 2005 - said: "The people out there in Hollywood with her
are in it for the money. They want to see what they can get. She needs to go
to rehab and my ex-wife Dina should go with her.
"The writing was on the wall years ago. She needs a faith-based program."

In other news, source connected to Lindsay Lohan's next movie says the actress' rehab will not get in the way of her performance, but TMZ has debunked the claim.

The production source told TMZ that arrangements had been made to shuttle Lohan back and forth from Promises in Malibu while Lindsay shoots the new Shirley MacLaine movie, "Poor Things," right down the road in Santa Monica.

A well-connected source tells TMZ that this "absolutely is not going to happen."

The first time she'll be available to work on the film will be when she's an outpatient -- probably a month from now.