UPDATE: A man who died from injuries sustained at an out-of-control party overnight was a father who was in the wrong place at the wrong time.
A 20-year-old man from Forrestdale was taken to Fremantle Hospital with serious injuries after police and St John Ambulance were called to the party on Lydon Boulevard about 1.30am.
"He has since died as a result of the injuries he received," police spokesman Samuel Dinnison said.
Police are looking for a white 2004 Mitsubishi ute - registration WN32158 - in relation to their investigation into the man’s death.
The driver is described as a fair-skinned male, 20 to 25 years old, about 175cm tall with a medium build, short blond hair and blue eyes.
Police have urged people not to approach the vehicle or the driver and to call triple-0 immediately if they see either of them.
The mother of one of three men injured at the 21st birthday party said her son and daughter, who was also at the party, were devastated to hear their mate had died.
She said all three victims had been stabbed by a man with what she believed was a steak knife.
Rachel Bowen's 21-year-old son Brodie Brouns remains in Royal Perth Hospital with a 13cm stab wound to his forearm.
Ms Bowen said police officers phoned her at 2am to say her son had been stabbed.
"[I thought] that he wasn't going to make it," she said.
"You hear 'stab' and you don't want to think about it."
Ms Bowen said she heard her son was a regular visitor to the house and the hosts had been like a "second family" to him.
The 20-year-old dead man, who has a two-year-old child, was a close friend of Mr Brouns.
Ms Bowen said her children were "gutted" to hear their friend had died.
"They've both lost a good mate," she said.
"It should never have happened.
"I had to ring my son to tell him that his mate had died.
"The boy who was killed doesn't go to parties, he's a good kid. Wrong place, wrong time."
Mr Brouns told his mother he needed plastic surgery and felt lucky to have suffered only minor injuries.
A third male, 22, who also was injured at the party, remains in Fremantle Hospital.
Neighbour Robert Golding said he heard a man and a woman arguing and screaming before police arrived.
The area was normally quiet and the home where the incident happened was not a regular party venue, he said.
"I've lived here 10 years and this is the worst thing that's happened," Mr Golding said.
Police have closed part of the street this morning as forensics officers and detectives investigate at the scene.
Major Crime Squad detectives have taken over the investigation.
Anyone with information about the party violence is asked to contact Crime Stoppers on 1800 333 000.
MORE TO COME