Police have theorized that Brooke Costanzo exited a nearby highway and somehow ended up on a dimly lit road.
The family of a popular high school junior who died Monday from injuries she suffered in a one-vehicle accident are trying to piece together how the 16-year-old, who absconded from the family's Saddle Brook home Sunday night in her mother's SUV, ended up crashing nearly 50 miles away.
Brooke Costanzo, 16, died about 6 a.m. Monday in Robert Wood Johnson University Hospital, about 12 hours after she lost control of the Honda Pilot she was driving and struck a tree on Fresh Pond Road in South Brunswick.
The Saddle Brook High School junior only held a learner's permit, and had taken the car without permission.
"We can't even fathom how this could have happened," said her uncle, Vincent Costanzo of Morristown.
Brooke Costanza in an undated photoPhoto courtesy of Costanzo family
Police have theorized that Brooke Costanzo exited a nearby highway and somehow ended up on the dimly lit road, he said.
"It's a long country road and it bears to the right really sharp," the uncle said.
It took first-responders about 40 minutes to free the teenager from the SUV. Vincent Costanzo said police officers were unable to find his niece's phone in the wreck.
He said family members are hopeful text messages or emails will provide clues as to why she was in Middlesex County.
"They did everything they could to find the phone," her uncle said. "We're hoping they do find it. Without out, we're stuck with a big mystery."
South Brunswick police have not returned calls seeking information about the crash.
Saddle Brook Mayor Robert White described Brooke Costanzo, a cheerleading coach and athlete, as "very, very intelligent and bubbly kind of person - curious, vivacious and precocious."
Brooke Costanzo in an undated photoPhoto courtesy of the Costanzo family
"It's a terrible loss," said schools Superintendent Anthony Riscica. "She was very well-known, very popular."
Riscica has worked with the girl's mother, Janine DiGirolamo Costanzo, who is involved in the district's competitive cheerleading program.
In addition to her duties as a cheerleader, the teen coached pee-wee cheerleading and was a talented lacrosse and volleyball player. She also helped in the district's before-care and after-care programs, Riscica said.
White, who met the family while he worked for the police department, said she often babysat children in the community.
"She had this mothering instinct and when she saw babies she just melted," said her uncle, Vincent Costanzo. "She was a good kid with a heart of gold."
"Tough shell on the outside, a soft little girl on the inside," he said.
Counselors will be available this week at the high school for anyone who "needs to talk with someone," the superintendent said.
By Tuesday morning, a GoFundMe page set up to help the family had raised nearly $31,000.
A candlelight vigil in the teen's memory will be held from 5 to 8 p.m. Tuesday at Saddle Brook High School, 355 Mayhill St., according to school officials.
The teen's death also marks the second time in six years the Costanzo family is mourning the loss of a loved one killed in an accident.
Brooke's father, Timothy Costanzo, died in a motorcycle crash in 2011.
The 51-year-old father of three was killed when his motorcycle struck a dip in the road and he was thrown into a concrete divider.
His daughter was just 10 years old.
Brooke Costanzo with her father, Timothy, who would later die in a motorcycle crash when Brooke was just 10 years old. Photo courtesy of Vincent Costanzo
"It was a devastating loss and a difficult time for the community," White said Tuesday. "I can't imagine what the family is going through now."
In addition to her mother, the teen is survived by twin sisters Samantha and Paige, who are students at the University of Rhode Island.
The Aloia Funeral Home in Garfield is handling funeral arrangements, which were expected to be complete by Tuesday afternoon.
Brooke Costanzo with her mother Janine and twin sisters Paige and Samantha. Photo courtesy of Vincent Costanzo
Anthony G. Attrino may be reached at tattrino@njadvancemedia.com. Follow him on Twitter @TonyAttrino. Find NJ.com on Facebook.