Last November’s terrorist attacks in Paris marked the first time that Facebook had deployed its Safety Check feature in a situation that wasn’t a natural disaster. Yesterday, the function was used for the first time in the US after a gunman massacred 50 people at an Orlando, Florida nightclub.

After seeing the way that social media was used to contact family and friends in the aftermath of the 2011 earthquake and tsunami in Japan, Facebook started work on the Disaster Message Board, which was renamed Safety Check prior to its 2014 launch.

The tool lets Facebook users near the scene of a disaster or other deadly incident to confirm that they are okay by simply clicking a button. It also allows searches for anyone who may be in the affected area. The feature has already been used in the wake of two Nepalese Earthquakes and during Pacific Hurricane Patricia in 2015.

After 29-year-old Omar Mateen - now confirmed as a G4S employee at the time of the shooting - killed 50 people and injured 53 others with an assault rifle at the LGBT nightclub, Facebook’s Safety Check was activated.

“Following the community-generated Safety Check activation this morning in Orlando, we have now activated Facebook-initiated Safety Check for a mass shooting at a nightclub there. We hope the people in the area find the tool a helpful way to let their friends and family know they are okay,” a Facebook spokeswoman said.

Initially designed to help those affected by natural disasters, the Safety Check is increasingly being used in the aftermath of terrorist atrocities. In addition to yesterday’s shooting and the Paris incident, it was activated following the Lahore, Boko Haram, and Ankara bombings, as well as the attacks in Brussels.

Between January and May this year, Safety Check was deployed 17 times. Across the entirety of the previous two years the feature was activated on just 11 instances.