A father threw his two children from a 15th floor balcony before jumping to his own death, police have said.
The boys and their father died when they landed on a rooftop
Edward van Dyk, 43, killed his two sons - aged four and eight - when he tossed them from a hotel balcony in Miami.
Van Dyk's wife Qinuo, 40, spotted him as he leapt from the balcony, and only then saw the bodies of her two children lying motionless many floors below.
Mrs van Dyk told police that the couple were having marital problems, but were marking their 10th wedding anniversary.
"It's a terrible tragedy," said Miami Beach Police spokesman Bobby Hernandez.
The killings took place at the Loews Hotel in the famous art-deco district of Miami's South Beach.
"It's unfortunate that this gentleman was so selfish and in an effort to get back at his wife he took the two most loved people in the world away from her," Mr Hernandez added.
Mr van Dyk had worked for 18 months as radiation oncologist in a cancer unit at a hospital in the family's home town of Alton, Illinois.
He left no clue explaining his actions, Mr Hernandez said.