Latonia Renee Lyons worked hard to support herself and three teenage children.

The 36-year-old single mother from Dallas began working a year ago as a nurse's aide and had enjoyed a day off Friday after a grueling week of working double shifts at a northeast Dallas assisted living center.

"She had been working doubles trying to pay her bills and take care of responsibilities," said Lyons' sister Veronica Lyons.

While on her way to work Saturday morning, Lyons was killed when a passing motorist in a Porsche Cayman struck her disabled Ford Taurus on U.S. Highway 75 about 6 a.m.

The 30-year-old man, whose name police withheld, was not charged, but police said a criminally negligent homicide case was filed and will be referred to a grand jury.

"Although it was dark at the time of the crash, [suspect] had a sight line of over 900 feet," an officer noted in a police report.

Lyons was driving north on the expressway when her Taurus stalled just north of SMU Boulevard in the 6200 block of North Central Expressway.

She turned on her flashers and pulled to the right shoulder as best she could but left a portion of her car in the far-right driving lane. The other motorist, who according to police reports "failed to control speed," hit the back of Lyons' Taurus, sending it flipping end over end with her inside before it came to rest on its roof 60 feet away.

Dallas Fire Rescue responders had to cut Lyons from the wreckage. She was taken to Baylor University Medical Center where she died.

The Porsche also flipped and crossed all five lanes of the highway before it stopped about 260 feet north from where the crash occurred. The driver was treated for minor injuries at the scene. Police are still investigating but said drugs and alcohol were not believed to be factors in the crash.

Veronica Lyons said her older sister – the eldest of four – cherished her family. She enjoyed spending time with her three teenage children. Veronica said she and Latonia would frequently meet for a "Girls Night Out," which included dinner and a movie.

"We were so much together, you thought we were twins," said Veronica Lyons. "Once you see her you'd see me."

Funeral services for Lyons are pending.