Feb. 10, 2010 -- Australian twins Angela and Maryanne Vourlis logged on to Facebook the morning of their 20th birthday, expecting to find birthday messages from friends, but instead they learned the heartbreaking news that their 17-year-old brother was killed in a fatal car crash.

"I didn't get it. All these people were writing, 'RIP Chris Naylor' and 'RIP Bobby,' and I thought: 'What's going on?'," Angela Vourlis told the The Daily Telegraph in Sydney.

Wondering if there had been a mix-up, she tried to call her brother. When she failed to reach him, she called their mother.

"So I rang Mum and said, 'Chris Naylor must have died -- I just read it on Facebook. But where's Bobby? People are writing 'RIP Bobby' too," Angela Vourlis told the Telegraph. "Mum said 'Bobby was with Chris Naylor last night'."

When the family called the police, they confirmed the news that had already spread across Facebook -- their son and brother had indeed died.

Police Spokesman: Authorities Can't Jump to Conclusions

"It's every parent's worst nightmare to lose a child in a car accident, but to have to hear it on Facebook, then have to chase up the police yourself, is just horrifying," Peter Matelis, Bobby's uncle, told the Telegraph.

A spokesman for the New South Wales Police Force confirmed for ABCNews.com that the Vourlis family had learned of Bobby Vourlis' death on Facebook, before authorities had a chance to alert the family themselves.

But he defended the police department's actions, saying that due to the nature of the crash, it took longer than usual to confirm his identity.

"[Police] can't jump to conclusions," he said. "Police understand the trauma of families in these situations and sympathize with the plight of the Vourlis family. But St. Marys Police [which is one station in the greater New South Wales Police Force] believe they did all they could in these circumstances to inform the family as soon as they did."

Nature of Crash Contributed to Delays in Identifying Victim, Informing Family

Along with Bobby Vourlis, two other teenagers died shortly after 3:15 a.m. on Feb. 7, when they struck a pole on a New South Wales highway, while traveling in a Ford sedan.

The driver, the 19-year-old Naylor, and Kelsie Coleman, 15, who was sitting in the back seat, also died. According to the Telegraph, two other teenage rear-seat passengers were taken to a local hospital and treated for multiple non-life threatening injuries.

The wreckage at the crash scene and the multiple fatalities contributed to the delay in identifying Bobby Vourlis and informing his family, the police spokesman said.

"Police did all they could to handle this sad task with care and sensitivity," he said, adding that the rapid pace of social networking sites complicated this particular case.

"Word spreads among young people very quickly and they're very savvy, tech-wise. Without confirmation [from police] they had alerted the family," he said.

Messages of Hope, Remembrance Spread on Facebook

But though Facebook was initially the messenger of tragedy, it has also become the messenger of hope.

On the social networking site, friends of the three dead teenagers have posted messages of remembrance and support for the Vourlis, Naylor and Coleman families.

"R.I.P CHRIS NAYLOR... tommorro [sic] is not going to be easy we all need to be strong my deepest sympathys go out to the naylor family..." wrote one friend.

"life is way too short, live it up and dont take it for granted, its times like this when you realise things like this," wrote another.

Facebook fan pages for the three teenagers have also appeared, in some cases drawing thousands of supporters.

"R.I.P. Bobby Vourlis, Chris Naylor and Kelsie Coleman" has more than 4,000 members and hosts photographs, video and discussions from bereaved loved ones. Dedicated pages for each of the deceased teenagers have also come online.

In October 2009, Facebook announced that families and friends of deceased members will be able to contact the site to have their loved ones' profiles memorialized. When an account is memorialized, other members will no longer see that person appear in their "Suggestions," and the privacy settings are changed so that only confirmed friends can see the profile or find it in search.

"When someone leaves us, they don't leave our memories or our social network," Facebook wrote on its blog at the time. "To reflect that reality, we created the idea of "memorialized" profiles as a place where people can save and share their memories of those who've passed."