Two sisters in Indiana were just sitting on the couch watching TV. No one could have predicted what would happen next.

A mother screams for help. Her daughters are trapped under a car, in their living room. And this teenager in tears is accused plowing into the house, running over the two young girls.

Barely old enough to drive, police say Alia Sierra was high and traveling over 100 miles per hour when she lost control and crashed through a family's living room, a crash that in an instant claimed the lives of two sisters -- and their mother's heart.

What began as a typical summer night at the Fullerton family's home in Frankfort, Indiana quickly turned to sheer terror and panic in July.

Shortly after 9 o'clock, sisters Haleigh and Callie were watching TV in the living room, when police say a Honda Accord came barreling into their home at 107 miles per hour.

The impact was so great that Bridget Fullerton's mother-in-law next door believed there had in fact been an explosion.

The car even knocked the home off its foundation as it careened through the family's living room, nearly exiting the other side.

Both Haleigh and Callie were pinned underneath the vehicle. The girls' brother Jacob and their grandfather desperately tried to free the girls.

But it was too late, the sisters were pronounced dead at the scene. They were likely killed the instant police say 17-year-old Alia Sierra drove into their house.

Tire marks in the grass show the car's deadly path. Alia unable to avoid the house even though it sits some 100 yards from the road.

Police say not only was she speeding, Alia Sierra tested positive for opiates. Reporter Alexis McAdams from Crime Watch Daily Indianapolis affiliate WXIN-TV says that according to a police affidavit, the three passengers riding with her were begging Sierra to let them out of the speeding car before the crash.

Due to the seriousness of the crime, prosecutors charged the teen as an adult.

In court Alia Sierra pleaded not guilty to 10 felonies. And even though the charges could send her to prison for decades, that's little consolation for the parents who lost their only two daughters.

For now, Alia Sierra is out of jail and under house arrest. She's able to attend school and work part-time wearing a GPS monitor. Her lawyer is appealing the decision to have her tried as an adult. She'll be back in court next month.