A family in upstate New York is reeling from the loss of four daughters – along with three of their husbands – in a weekend limousine accident that claimed a total of 20 lives.

"Horrific"

"Twenty fatalities is just horrific," National Transportation Safety Board (NTSB) Chairman Robert Sumwalt said at the news conference. "I've been on the board for 12 years and this is one of the biggest losses of life that we've seen in a long, long time."

The NTSB is investigating the tragedy, which occurred when the limousine driver failed to stop at an intersection in Schoharie, New York, ploughed through a parking lot and crashed into an unoccupied SUV. Among the dead were two pedestrians struck by the SUV.

All 18 people in the limousine died. They had hired the vehicle as part of a surprise 30th birthday celebration for one of the sisters. The crash occurred shortly after 1 p.m. on Saturday.

The victims identified so far include Amy King Steenburg and Axel Steenburg; Rich Steenburg; Mary King Dyson and Robert Dyson; Allison King; Abby King Jackson and Adam Jackson; Erin Vertuccci McGowan and Shane McGowan; Matthew Coons; Savannah Bursese; and Patrick Cushing. The victims identified so far range in age from to 30 to 35.

A steep hill led to intersection

Sumwalt said the NTSB would be looking at including road conditions, mechanical conditions of the limousine, and emergency response.

News sources say the intersection at the site of the crash was known to be dangerous, and that large trucks were banned from descending the steep hill that led to it after a number of them failed to stop and ended up in the same parking lot as the limousine.