Facebook activates Safety Check after truck attack kills dozens in Nice, France - CNET

Facebook activated its Safety Check feature on Thursday after a truck rammed a Bastille Day celebration in Nice, France, killing at least 73 people and injuring scores more.

It's the third time in a little more than a month that the social network has activated the tool, which lets Facebook users who are at or near the site of a natural disaster or terrorist attack inform their friends on the network that they are safe. The tool was put into use in early June after the deadly attack on an Orlando, Florida, night club claimed the lives of 49 people and again less than two weeks later after suicide bombings at Istanbul Ataturk Airport that claimed at least 45 lives.

"Last month, we began testing features that allow people to both initiate and share Safety Check on Facebook," a Facebook spokesperson said in a statement. "We hope the people in the area find the tool a helpful way to let their friends and family know they are OK."

Safety Check automatically sends Facebook users in an affected area a note asking if they're safe. When a user clicks on "yes, let my friends know," the tool notifies their Facebook friends.