MENLO PARK — The dark thoughts that flow through the minds of people contemplating suicide might find their way to a social media site, and Facebook wants to make it easier for friends and family to help.

The tech firm on Tuesday said it is rolling out worldwide tools aimed at preventing suicide, expanding its reach beyond the United States. Working with mental health groups such as Forefront, Lifeline and SAVE.org, Facebook started working on suicide prevention about a decade ago after a string of teen suicides in Palo Alto.

Since then, as Facebook has grown to 1.6 billion users worldwide, social media is playing a larger role in how people — especially teens — share their thoughts and lives with others. At the same time, social media sites such as Facebook are grappling with the technology's negative sides, including cyberbullying.

"Now, with the help of these new tools, if someone posts something on Facebook that makes you concerned about their well-being, you can reach out to them directly — and you also can also report the post to us," Antigone Davis, Facebook's global head of safety, and Jennifer Guadagno, a researcher for the company, wrote in a post about the topic.

Facebook, which says the information is confidential, sends resources to the person who might be in trouble, asking them if there's a way the company can help. Talking to a friend, contacting a hotline, getting tips and support, or skipping the notice are among the options available in the drop-down menu. If you or someone you know is in physical danger, it's important to call law enforcement, the company said.

In 2014, there were 42,773 deaths by suicide in the United States, making it the 10th-leading cause of death in the nation, according to data from the Centers for Disease Control and Prevention.

Nearly two-thirds of American adults use social networking sites, a 2015 report by the Pew Research Center shows. Facebook, the world's most popular social media site, leads the industry with its use of suicide-prevention tools, said Dan Reidenberg, executive director of SAVE.org or Suicide Awareness Voices of Education.

"Social media has a tremendous opportunity to be a part of the solution to save lives. They can't do it alone," Reidenberg said.

With Facebook first releasing the tools in the United States in 2015, Reidenberg said it's too early to tell how well they've been working, but he has heard anecdotally people are impressed with the new features.

But the tools also drew some criticism from advocacy groups, including Consumer Watchdog, which raised concerns that Facebook wasn't doing enough to protect users from the misuse of the tools. In March 2015, the group sent a letter to Facebook CEO Mark Zuckerberg after San Mateo resident Shane Tusch claimed he was experimenting with the tool by posting a fake suicide note and ended up in a mental health facility for 70 hours.

San Mateo police said Facebook didn't call them about Tusch, according to news reports.

"I just have some lingering concerns from the time it was rolled out. It's not necessarily clear to me if those issues have been resolved," said John Simpson, director of Consumer Watchdog's Privacy Project.

Meanwhile, there have been suicide notes posted on social media sites that weren't false alarms. In October, Ashley Hallstrom, a 26-year-old transgender Utah woman, wrote a suicide note on Facebook before walking into traffic, where she was killed by a dump truck, according news reports.

"These are going to be my final words," Hallstrom's post read. "I can't stand to live another day, so I'm committing suicide."

Contact Queenie Wong at 408-920-2706. Follow her at Twitter.com/QwongSJ.