NEW YORK — When they boarded a small plane bound for upstate New York this past 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 to 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 on Saturday, the twin-engine plane they were traveling in 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.

— The Associated Press