The limo driver, all 17 passengers and the two pedestrians died in US's deadliest car crash in a decade.

Two pairs of newly weds, four sisters from one family and two brothers from another were among the 20 victims when a stretch limousine taking passengers to a surprise birthday party crashed in upstate, New York, according to media reports on Monday.

Federal authorities described Saturday's accident as the deadliest US transport crash in nearly a decade.

Officials had not released the victims' names as of early Monday, but some of the names and details were disclosed by media accounts from relatives and Go Fund Me pages on the internet.

Erin and Shane McGowan were just starting a life together after five months of marriage, the Times Union of Rochester, New York reported.

The McGowan's were a part of a party of 17 young adults who climbed into a stretch limousine 2001 Ford Excursion to celebrate their friend Amy Steenburg's 30th birthday, the paper and other media reported.

They were headed to an upstate New York brewery, but never made it, officials said.

The limo charged through a highway intersection without stopping on Saturday afternoon, in Schoharie, New York, about 40 miles (65 km) west of Albany, police and the National Transportation Safety Board (NTSB) said.

It crashed into an unoccupied parked car and hit two pedestrians before coming to a rest in a shallow ravine, officials said.

The limo driver, all 17 passengers and the two pedestrians died, state police and the NTSB said.

Amy Steenburg was also a newlywed. She and her three sisters - Mary Dyson, Allison King and Abby Jackson - and her husband Axel Steenburg and his brother, Rich Steenburg, all died, relatives told The New York Times.

Barbara Douglas, the aunt of the sisters, said the victims were smart, beautiful and lived life to the fullest.

"I don't know how you say it. You can't wrap you head around such a tragedy where you have four of your daughters die," she told reporters at the scene.

NBC news reported that Mary Dyson's husband Rob Dyson also died.

It was the deadliest transportation accident in the United States since a 2009 plane crash in Buffalo, New York, that killed 49 people, NTSB Chairman Robert Sumwalt told a news conference on Sunday.

State Police are probing the cause of the crash.

© Thomson Reuters 2018