MANORVILLE, Long Island (WABC) -- A sixth person has died in a multi-vehicle crash on a major Long Island roadway over the weekend in which speed is being closely examined.
The latest victim to die in the violent crash on the westbound Long Island Expressway in Manorville Sunday morning was the 71-year-old wife of an 81-year-old man, who also died in the crash. Others killed include a family a three from Hempstead and a former aide to New York Gov. Andrew Cuomo.
Police said the driver of an eastbound Subaru Outback, Carmelo Pinales, 26, of Hicksville, apparently lost control of his vehicle, which crossed over the grassy median, went airborne and struck two vehicles, a BMW and a Honda, that were traveling westbound.
Pinales and his 27-year-old sister, Patricia Pinales, of Westbury, were pronounced dead at the scene. His 10-year-old son, Christopher, was taken to a hospital, where he later died. Two others in that vehicle, including Patricia's 3-year-old daughter, were injured.
PHOTOS: Scene, victims in Long Island Expressway crash
The large, tight-knit Pinales family, which has about 60 cousins who live nearby, gathered Sunday night still in shock, saying they feel like it's a nightmare they can't wake up from.
"They all live together - they live in one house, so one day the whole household disappears," said the victims' cousin, Liliana Hart.
VIDEO: Recap of tragic crash
Hart says her cousins were inseparable, and were always the life of the party. They died in the horrific crash just minutes from their destination, a water park to celebrate Christopher's birthday.
Also killed in the crash was Scott Martella, a Communications Director at the Office of Suffolk County Executive Steven Bellone. He also worked previously for Governor Andrew Cuomo's office.
Martella's fiancee, 29-year-old Shelbi Thurau was transported to a local hospital where she is being treated for non-life threatening injuries.
"He had such a respect for people, and he was so committed to helping people and he really did that in his unfortunately too brief life," said Bellone. "He touched so many lives."
Cuomo, a Democrat, said Martella served in his administration for more than four years. The governor spoke Monday about Martella's dedication to public service.
"He worked for me for a number of years, this was a really beautiful young man," said Cuomo. "He just loved public service, he loved helping people."
A passenger in the BMW, Isidore Adelson, 81, of Westhampton, was taken to a hospital, where he succumbed to his injuries late Sunday. Adelson's wife, Helen, died Monday. Two others in the BMW were injured.
Relatives of the Pinales' family say they believe an earlier accident left an oil spill, which contributed to the crash.
(The Associated Press contributed to this report.)