Three siblings were killed after their car slammed into a toll booth in New Jersey and burst into flames.

The crash happened just after 9 p.m. local time Sunday at the Egg Harbor Toll Plaza along the Atlantic City Expressway in Hamilton Township, state police said.

The driver, Reachthon "Tonny" Khiev, 31, and front seat passenger, Reachsieh "Johnny" Khiev, 27, both of Manchester, New Hampshire, were killed, along with their 14-year-old sister Keotepie Khiev, who was sitting in the back seat.

Three siblings die in crash
Reachthon "Tonny" Khiev, 31 (L), Reachsieh "Johnny" Khiev, 27 (C), and their 14-year-old sister Keotepie Khiev (R) were killed in a car crash in New Jersey.GoFundMe

Their 12-year-old sister, who was also in the back seat, and a toll booth attendant were taken to hospital with injuries that were not considered life-threatening. The cause of the crash remains under investigation.

Jimmy Giang, a family friend, told WPVI that the brothers had surprised their younger sisters in Atlantic City for Christmas and spent the day shopping. He said he had been with them for dinner before the crash happened, and stressed that no one had been drinking or under the influence of any substance.

"Johnny and Tonny were visiting their little sisters from New Hampshire to surprise them for the holiday weekend," their sister Mimi Khiev wrote on a GoFundMe page that has quickly garnered more than $36,000 in donations.

"They were on their way back home to drop off their sisters from a day full of shopping and dinner. Unfortunately, it was their best and last Christmas as a family."

According to the GoFundMe page, the brothers were born in Cambodia and moved to the U.S. when they were young. They worked as in-home care providers for people with disabilities.

"Their caring nature not only translated through their career, but also through their endless kindness to everyone they encounter," Mimi Khiev wrote. "They both had aspirations of opening up a donut shop and moving their whole family to live with them in New Hampshire."

Her post described her sister Keotepie, a ninth grade student at Atlantic City High School, as a "beautiful, intelligent and very sweet girl."

The page also noted that the brothers had been the ones financially supporting the family.

An update on the page said the Khiev family sends "their sincerest gratitude" for the donations collected. It said the money raised would cover funeral expenses for the three siblings, and remaining funds would help the sister who was injured in the crash with medical expenses and "used to fulfill Tonny and Johnny's hopes of moving the rest of his family to New Hampshire so they can be closer with each other during this tragic time."

The New Jersey State Police and Khiev family have been contacted for comment.