At 2:45 Tuesday afternoon, I-95 in Port Chester just below the 287 underpass was the spot where two families' lives changed forever.
"It's very unusual and not something you would expect if you were driving they were not doing anything inappropriate obeying all the rules and it's just a freak accident," Commander Evelyn Mallard said.
Police say 62-year-old Adele Mancuso of Larchmont was behind the wheel of the Chevy Cavalier.
Her mother 82-year-old Constance Casalina was along for the ride.
On the opposite side of the highway, a flat bed tracker trailer was heading southbound getting onto the exit 21 ramp.
"He lost two rear wheels from the right side of the truck which hit the guard rail, went airborne, crossed three lanes of traffic, and struck a Chevrolet that was traveling northbound in the center lane," Mallard said.
One wheel went 150 feet in the air, caving in the hood, blowing out the windshield, and mangling the Chevy's frame.
Mancuso was killed instantly.
Her mother was rushed to Stamford Hospital.
Her son stopped by the nightmare on the way to the hospital.
It was all while investigators talked to witnesses getting every lead that pointed to where to find the driver of that tractor trailer.
"The vehicle kept going. It's unknown if the driver knew he lost the rear wheel section because it is an 18-wheel tractor trailer. We do believe we know who the operator and trucking company is," Investigator Joseph Pecerra said.
That driver was brought in for questioning Tuesday evening.