Former Worthing College students Becky Dobson, 27, Jason Hill, 32, and Stuart Hill, 30, died on Saturday when the helicopter came down on a tour of the canyon, also leaving three other Britons injured.
Paul Riley, principal of Worthing College, said: “The whole college community will be utterly devastated to hear the news that three of our alumni have died under tragic circumstances.
“We will do all we can to support family and friends at this difficult time.”
He confirmed that Miss Dobson attended the school in Sanditon Way for one year from 2009 to 2010, studying fine art and health and social care.
Stuart Hill studied A Levels in psychology, photography and media studies at the school from 2004 to 2006, he said.
Jason Hill studied A Levels in English Literature, Government and Politics, and Law at the school from 2002 to 2004, as well as studying history at AS Level.
There has been an outpouring of emotion on social media following the tragic news.
Councillor Edward Crouch wrote online: “My heart goes out to the family and friends of Becky, Stuart and Jason.
“I went to college with Jason and knew him to be witty, intelligent and a great friend to those who knew him. Utterly tragic.”