Five of the 10 Americans killed in aon Sunday were members of a suburban New York family, the sister of one of victims confirmed to CBS News. Tamara Steinberg Jacobson confirmed her brother, Bruce, his wife Irene and their three sons, Matthew, William and Zachary, were aboard the plane.
"We are in utter shock and disbelief right now," Bruce Steinberg's sister, Tamara Steinberg Jacobson, wrote on Facebook.
Rabbi Jonathan Blake of the Westchester Reform Temple in Scarsdale said the Steinbergs were involved in philanthropy and local Jewish groups. "They will be deeply missed," he told the New York Post.
The other Americans have not yet been identified. Two local Costan Rican crew members were also killed in the crash.
At a news conference, Enio Cubillo, director of Costa Rica Civil Aviation, said the Nature Air charter flight took off just after noon Sunday from Punta Islita and was headed for the capital of San Jose when it crashed.
Cubillo said the cause was under investigation.
He identified the pilot as Juan Manuel Retana and described him as very experienced. Former Costa Rican President Laura Chinchilla said via Twitter that Retana was her cousin.
The same plane had arrived in Punta Islita on Sunday morning from San Jose and was delayed in landing by strong winds, Cubillo said.
Nature Air did not respond to phone and email messages.