NEW YORK >> When they boarded a small plane bound for upstate New York this weekend, the six passengers — a pair of close-knit siblings, their parents and partners — were on the cusp of a new chapter in a family life already replete with personal and professional accomplishment.

Karenna Groff, a one-time collegiate soccer star at the Massachusetts Institute of Technology, was celebrating her 25th birthday with her longtime boyfriend, investment banker James Santoro, to whom she planned to get engaged this summer.

They were joined by Karenna’s brother, Jared Groff, 26, a former basketball player at Swarthmore planning his own proposal to his girlfriend Alexia Couyutas Duarte, a 24-year-old Colombia native set to start at Harvard Law School in the fall.

Shortly after noon Saturday, the twin-engine plane crashed into a muddy field in Copake, New York, killing both young couples and the Groffs’ parents, Dr. Michael Groff and Dr. Joy Saini — each celebrated surgeons.

“They were all so accomplished, but it was never about their accomplishments,” James Santoro’s father, John Santoro, told The Associated Press. “Everyone considered them such a bright spot in their life. I’m sad for myself and my family, but I’m sad for everyone else who’ve lost them too.”

On Saturday, the Massachusetts-based parents stopped off at Westchester County Airport in White Plains, New York, at 11:30 a.m. to pick up Karenna Groff and James Santoro before beginning the roughly two-hour flight north. The weather was slightly overcast and windy, with gusts around 25 mph.

Minutes before the landing, officials said, Michael Groff radioed air traffic control at Columbia County Airport to say he had missed the initial approach. As air traffic controllers prepared new coordinates, they attempted to relay a low-altitude warning but received no response. The wreckage of the aircraft, a Mitsubishi MU-2B, was later found spread over 100 yards of an empty field.

The tragedy has prompted an outpouring of grief and raised questions about the cause of the crash. Friends of Michael Groff described him as an experienced pilot who started flying as a teenager and often made the trip to his sister’s country house in upstate New York.

“Michael and Joy were wonderful, warm parents and distinguished physicians who treasured their children,” said Jonathan Becker, a family friend.

Their youngest daughter, Anika, was not on the flight.