Last Updated 9:16 p.m. ET
(CBS/AP) NEW YORK - An out-of-control SUV barreled across several lanes of traffic on a highway overpass Sunday, then plunged more than 50 feet off the side of the road and landed in a ravine on the grounds of the Bronx Zoo, killing all seven people aboard, including three children, authorities said.
The SUV apparently flipped over a 4-foot-high iron fence before landing upside-down on the property of the nation's largest city zoo. The cause of the crash was unclear, and police haven't yet said how fast the SUV was traveling. A city official said the guardrail's height would be one of the safety issues investigated.
The victims were three girls, ages 3, 7 and 10, an 85-year-old man and three women, ages 81, 45 and 39, police said. The 45-year-old woman was driving. The victims' names weren't immediately released. A police department spokesperson confirmed that all were members of the same family.
The Honda Pilot was headed south on the highway that cuts through a working-class neighborhood when it bounced off the median, crossed all southbound lanes and hit the guardrail, police said.
"Obviously, the vehicle was traveling at a high rate of speed," FDNY deputy Chief Ronald Werner said. "It hit something that caused it to become airborne."
The SUV landed in a wooded area on the edge of zoo property that's closed to the public and far from any animal exhibits, zoo spokeswoman Mary Dixon said. The vehicle lay mangled hours later, its right doors ripped off and strewn amid the trees along with items from the car. Next to the heavily wooded area are subway tracks and a train yard.
It's not clear what caused the SUV to go out of control. The southbound side of the highway was closed briefly Sunday afternoon while police investigated but later reopened.
The medical examiner's office said it expected to release the victims' causes of death on Monday.
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.
In June, 2011, in a similar accident, the driver of an Acura SUV going north on the Bronx River Parkway lost control. The vehicle hit a divider embankment, bounced through two lanes of traffic and plunged 20 feet down over a guard rail, landing on a pickup truck in a parking lot. There were no fatalities in that accident.