In 2011, when a deadly tsunami set off 30-foot tidal waves that crashed into the shores of Japan, flooding entire cities and damaging nuclear power plants, Facebook became an instrumental tool in connecting loved ones and alerting family members to their safety.
The social network is now rolling out a new check-in feature for use during such natural disasters. Safety Check, as the new product is called, was unveiled by CEO Mark Zuckerberg Thursday afternoon in Tokyo, and is meant to help Facebook users quickly alert friends and family that they are safe during times of crisis, like earthquakes or tsunamis.
Safety Check works by sending users a push notification asking them if they are safe whenever a natural disaster strikes the area they list as their current location. User’s can then see a list of their Facebook friends in the area, and see which users have checked in as safe and which have not.
Facebook will determine what constitutes a disaster worthy of a check-in by communicating with local authorities and experts, says Marcy Scott Lynn, global policy programs manager at Facebook. Safety Check has a few added elements — for example, you can check in for a Friend, and Facebook will ask you to check in if it sees you are traveling in a compromised area — but for the most part, Safety Check is intended for sharing one simple status: Yes, I’m fine.
The initial idea for Safety Check came from Facebook’s Japan office following the 2011 earthquake and ensuing tsunami, hence Zuckerberg’s announcement in Tokyo. Employees at the time developed a Disaster Message Board within Facebook to help families and friends connect in the wake of potential disasters, but the tool was limited to Japanese users and slowly faded as Facebook continued to evolve.
Eleven months ago, product manager Sharon Zeng and software engineer Peter Cottle picked up the project during a company-wide hackathon at the company’s headquarters in Menlo Park, Calif.
Facebook didn’t partner with any outside organizations on the project, so for now, if a user does not check in during a disaster, authorities won’t be notified in any way. It’s possible that Facebook could partner with groups like the Red Cross down the road, but there are no partnership plans in the works, according to Lynn. “We recognize this tool isn’t for everyone or every time,” she added. “It wasn’t designed as a first responder tool.”
Other online communities, including Twitter, have also added features for sharing important information during natural disasters. Facebook’s Safety Check is now active for all 1.3 billion users.
This article originally appeared on Recode.net.