Faisel Tubbal is sleep-deprived but jubilant after celebrating the "happy" news that Colonel Muammar Gaddafi was dead.Mr Tubbal's family had particular reason to loathe the hated former Libyan dictator.In February this year, Mr Tubbal's brother Osama was one of the first people shot and killed by Gaddafi's henchmen following the rebel uprising.Osama, 28, was at a protest in Rujban City, about 160km south-west of the capital Tripoli, on February 16, shortly before the mass killings broke out.Osama confronted a general after he was called a "dog"."My brother said, 'I am not a dog and I am not afraid of your weapon'," Mr Tubbal said. "He shot him."Yesterday, grief was mixed with celebration as the family learned Gaddafi had suffered the same fate.Mr Tubbal, a Libyan-born father of three studying engineering at the University of Wollongong, said he had been awake since the early hours, watching the television while fielding calls from Libya."One of the calls is the most important one for me, was from my mother," he said."She told me she was feeling happy because my brother was killed at the beginning of this revolution and ... she was crying all the time. Last night she called me and she told me, 'I feel now this is the justice, since he killed me son'." Mr Tubbal, 32, said 2011 was "a most important year"."Many people were killed, now Gaddafi also killed. He was a terrible man. Not only did he kill his people, he killed people everywhere."It's now safe, not only for Libya but the whole world which makes me very, very happy."A joy for Mr Tubbal's family is that his baby son, born at the time of his brother's death and named in his honour, is thriving.Prime Minister Julia Gillard and Foreign Minister Kevin Rudd were quick to join other world leaders in welcoming a new beginning for the North African country after the 69-year-old's death.But they said the nation's journey to a fully functioning democracy was far from over."The work ahead to unite Libya, to establish law and order, and to rebuild its economy and its towns and cities will be challenging," Ms Gillard and Mr Rudd said in a joint statement.Mr Rudd was an early and vocal advocate of international military intervention in Libya.Australia has also been one of the biggest donors of humanitarian assistance to Libya.Deputy Opposition Leader Julie Bishop said Gaddafi's death presented Libya with a rare opportunity to become a more open and tolerant society.