45-year-old Richard Williams of Brooklyn, NY, is charged with three counts of death by auto. He is being held in the Mercer County Correction Center in lieu of $100,000 bail, authorities say.
25-year-old Jamella Tisdale was killed, along with 9-year-old Jaevon Durante and Jaden Tisdale, who was three and a half months old.
The driver of the SUV, 25-year-old Shaqwan Tisdale of Levittown, Pa., and 8-year-old Mellady Durante remain in the hospital in stable condition.
The accident happened before 6:30 p.m. in the 2700 block of Brunswick Pike.
Investigators say the SUV hit the side of the tractor trailer with such force, the wheels embedded into the concrete, trapping the family in the mangled metal.
The Trenton Fire Department was brought in to help free the survivors.
Responders had to lift the trailer off the ground to free them.
What caused the accident is still under investigation. Detectives will look at speed and other factors.
It appears the trailer was making a left turn off southbound Route 1, but no conclusions have been made.