The accident happened on the Bronx River Parkway, near 177th Street, when the family's SUV crashed through the guardrail and plunged 60 feet into a wooded area of the zoo.
Police said at a briefing Monday that Maria Gonzalez was driving at 68 mph when she bumped the concrete barrier between the two directions of the highway and the left front tire went off kilter.
The posted speed limit on that stretch of the Bronx River Parkway is 50 mph. Police say she was likely going with the flow of traffic, which is often faster.
There's no evidence to suggest Gonzalez was texting or on the phone, said New York Police Department spokesman Paul Browne.
"There's no evidence of a mechanical failure, but the investigation is ongoing," Browne said.
Among the dead were three young girls, their mothers and their grandparents: 85-year-old Jacob Nunez, 81-year-old Ana Julia Martinez, both from the Dominican Republic; 45-year-old Maria Gonzalez and 39-year-old Maria Nunez, and 10-year-old Jocelyn Gonzalez, 7-year-old Niely Rosario and 3-year-old Marly Rosario. The medical examiner said all of the victims died from blunt force trauma. Toxicology tests were still pending.
It was supposed to be a weekend of celebrating for the tight-knit family, but it turned into a weekend of mourning.
"It's just me and my father and my little brother now," Jonel Gonzalez said, holding back tears. "She (mom Maria Gonzalez) started working at Fordham University to help provide for my schooling. She started working full time not too long ago. She was also a mother, a mother of three. She was a great wife."
"My sister went to St. Raymond Elementary," he said of Jaocelyn Gonzalez. "Her communion was this Saturday."
The vehicle landed in a wooded section of the zoo that is closed off to the public. No animals were there at the time. Police say everyone inside the SUV died on impact.
Werner said the crash scene, less than five miles from Gonzalez' Bronx home, was difficult to see, with contents of the van, including a pink schoolbag, strewn about.
"When you see young kids that have been hurt or injured or lose their life, it's always harder than if you find someone that's an elder age," FDNY deputy Chief Ronald Werner. "It affects all our units."
The accident was the second in the past year where a car fell off the same stretch of the Bronx River Parkway. Last June, the driver of an SUV heading north lost control and the SUV hit a divider, bounced through two lanes of traffic and fell 20 feet over a guardrail, landing on a pickup truck in a parking lot. The two people in the SUV were injured.
City agencies will be asked to look at safety issues on the highway including guardrail height, Bronx borough President Ruben Diaz Jr. said in a statement Sunday.
"My prayers, as well as those of my office and all Bronxites, go out to the families of the seven victims," he said.
The wreck was the deadliest in New York City since the driver of a tour bus returning from a Connecticut casino in March 2011 lost control and slammed into a pole that sheared the bus nearly end to end, killing 14 passengers.
In 2009, just north of New York City in suburban Westchester County, a woman carrying a vanload of children drove nearly two miles in the wrong direction on a highway before colliding with an SUV. Eight people were killed, including four children. An autopsy determined that the woman, Diane Schuler, had downed at least 10 drinks and had smoked marijuana as recently as 15 minutes before the wreck.
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