The cousin of Ben Simmons, who was picked first by the Philadelphia 76ers in the NBA draft, died after being struck by a sport utility vehicle in a New Jersey neighborhood, family members said.

Zachary Simmons, 21, died after being struck early Saturday while crossing a street in Hoboken. Authorities said the SUV that struck the Ramsey man fled the scene.

The victim's mother, Monique Steele, told WCBS-TV her son had gone with Simmons to the NBA draft earlier in the week. She said he was walking back from a friend's birthday party when he was struck and killed.

"To be speeding enough to kill my child is beyond me," Steele said, noting that police told her the SUV was going at least 70 mph at the time of the accident. The speed limit in the area where the crash occurred is 25 mph.

Hudson County Sheriff Frank Schillari told NJ.com that police are investigating pieces of the vehicle left at the scene and video footage.

Ben Simmons posted a photo Saturday night on Twitter showing him standing with his cousin. The caption read "#ripZacharySimmons" and stated "I'm glad I could share this moment in my life with you."

In another Twitter post, Simmons wrote that, "Hearing the news this morning is a reminder to never forget the important things in life."

Police were still searching for the fleeing vehicle Sunday afternoon. It wasn't known how many people may have been in the SUV when the accident occurred.