WATCH: North Texas Family Desperately Searches for Answers After Youngest Son Is Killed in Hit-and-Run

As a North Texas family prepares to bury the 29-year-old man who was a son, brother, and uncle, they’re making a desperate plea in the search for the person responsible for his death.

Robert Smith was at a bus stop in the 3200 block of East Lancaster Road in Fort Worth Tuesday night. A friend said he was standing just off the curb when a black or dark blue suburban was driving erratically before it hit Smith and left him for dead.

“We need to find out who did this and we owe that to Robert. We’re not going to stop. We’re not going to give up. We won’t quit until we find out who did this,” Smith’s sister Nati Andrews said.

Smith was the youngest of six.

“He had a big heart, and he was our little brother,” Andrews said.

The family said he spent most of his time as his mother’s caretaker.

“He was with me for 29 years, every day, all day. Wherever he would go, he would call and let me know where he was at and that he was on his way home,” his mother Mary Smith said.

Which is why she knew something was wrong when she didn’t hear from him Tuesday, Wednesday, or Thursday.

She said it was at the bus stop where he died where she was told what witnesses saw. And though another car tried to follow the driver who hit her son, no one was able to get a license plate number.

“We want that person to understand that they took a brother, a son, an uncle who was loved so very deeply. They took him from us, and he did not deserve this. He did not deserve to be hit,” Andrews said.

Anyone with information is asked to call Fort Worth police.

SOURCE: NBC 5 DFW  – Allie Spillyards