The 23-year-old woman was helping a dog who had been hit by a car when she was struck by a truck.
It happened on Weston Canal road in Franklin.
The victim has been identified as Tiffany Jantelle.
Flowers and a stuffed puppy mark the crash scene.
At her mother's home in Piscataway, Tiffany's equestrian trophies and ribbons line the walls. She loved animals, and died trying to save one.
"We are asking for help in trying to find the people who did this to her because she was such a great person, she didn't deserve to die like this," said Corrine Nellius.
Police say Tiffany was driving home from a bowling alley with friends when she saw a dog lying in the middle of the road after it had been hit by a car. Tiffany stopped to comfort the mixed-breed Shepherd and move it out of the road to safety, and that's when she and the dog were hit.
Police say the vehicle that hit her and later sped away was a black Dodge pick-up truck, either a 2500 or 3500 model. The truck is distinctive, it is lifted and has twin chrome vertical exhaust pipes that come up behind the cab.
"I see Tiffany and she tried to get away, of course she couldn't leave the dog and I saw him hit her," said Danny Owsic.
The truck eventually stopped and someone, either the driver or the passenger got out and approached Tiffany as she lay dying in the street.
Tiffany died early yesterday morning in the hospital. Also the dog she was trying to save had to be euthanized.
Police are working hard to track down the hit and run driver, several eyewitnesses got a very good look at his face or the passenger's face.
There's a $5,000 reward being offered leading to the arrest and conviction in this case.