The devastated family of a Melbourne teenager killed in a vicious screwdriver attack at a birthday party say their lives have turned into a dreadful nightmare .
Three men who gatecrashed the event in Tooradin are wanted by police after 17-year-old Jason Langhans was killed in an unprovoked assault described by police as brutal .
Heartbroken mother Carolyn Langhans struggled to hold back tears as she told reporters her beautiful boy had been ripped from their lives too soon.
Jason Langhans (left) pictured with his friend Tyler (right).(Victoria Police) There is a big hole in our hearts, she said. I m devastated, my heart is broken.