Thomas Bennett fell to his death from a block of flats at the University of Hawaii in Honolulu.
The 24-year-old landscape architect, who lived in Hawaii, tried to rescue the teen from a window ledge but the rescue attempt ended in tragedy when both fell.
'The word hero is banded about too freely, but what my son did was heroic'
Thomas was killed in the fall but the 19-year-old survived, although his condition is critical.
According to reports the teen suffered severe injuries, including two broken legs, a broken arm, a collapsed lung, an injured back and internal bleeding.
A Honolulu medical official said Thomas died as a result of injuries suffered in his fall.
Tom leaves behind his mother and father Lesley and Chris and siblings Annaliese, Emily, Ross and Isabelle.
"The word hero is banded about too freely, but what my son did was heroic," his mother said.
Sources: The Telegraph, The Mirror