– The tragic deaths of two teenage girls from Wisconsin in a 2006 crash left their families reeling and feeling they had no legal recourse against General Motors, even though the 2005 Chevrolet Cobalt in which they died is now the subject of a highly publicized recall.

More than seven years after concluding they could not afford to take on GM with the evidence they had at the time, the families of the girls have new lawyers and new evidence. They will be part of a legal challenge to GM’s shield from liability for deaths or injuries occurring in accidents before it exited bankruptcy in July 2009.

The families of Natasha Weigel, 18, and Amy Rademaker, 15, are part of a personal-injury lawsuit that could be filed as early as Monday alleging that GM fraudulently kept information about defective ignition switches from bankruptcy court. Last week, GM documents filed with federal safety regulators show that the company knew of a problem with ignition switches on Saturn Ions as early as 2001.

“I’m appalled and shocked and angry,” said Ken Rimer, Weigel’s stepfather. “Accidents can happen, but now we know this was not human error; it was a mechanical problem that could have been prevented.”

First test of legal immunity?

The lawsuit could be the first test of GM’s legal immunity granted when the government-funded bankruptcy left it free of old claims and lawsuits. The lawsuits remained with “old GM,” which holds assets and liabilities that are no longer part of the company.

New information is emerging daily about what and when GM knew about the ignition switches. It faces four investigations.

GM has recalled 1.6 million vehicles globally, including 2005-07 Chevrolet Cobalts, 2003-07 Saturn Ions, Pontiac G5s, Solstices and Chevrolet HHRs. The key in the ignition switch can be jostled into accessory mode, which disables the power steering, air bags and other electrical systems.

GM is advising owners to remove heavy objects from their key chains. Dealers will begin replacing the ignition switches next month.

Twelve deaths and 31 crashes have been linked to the defective switches amid suggestions the number could be higher.

On Oct. 24, 2006, a 2005 Cobalt containing three girls suddenly lost power, veered off the road and hit a grove of trees. Passengers Weigel and Rademaker died of their injuries. Driver Megan Ungar-Kerns survived but suffered severe head injuries. She has no recollection of the accident or events leading up to the deadly crash.

GM’s stance is that the families have no legal recourse because their accident occurred before 2009.