Hurricane Matthew has left a path of destruction across the Caribbean and is currently working its way towards the Bahamas and the United States. President Obama has declared a state of emergency while the Governor of Florida, Rick Scott, has told people to get out as "This storm will kill you".

Facebook activated its "Safety Check" feature, as it has done in the past for natural disasters and terrorist attacks. The simple check-in tool lets anyone in the affected area of the storm inform their friends and family that they are safe. 

"Our hearts go out to the people affected by this tragic event," Facebook 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 okay."

Earthquakes:

Facebook engineers began work on the feature following the 2011 earthquake and tsunami in Japan, inspired by people's use of social media to connect with their friends and family following the natural disaster. 

While it was officially introduced in October 2014, it was only first enabled in the wake of the Nepal earthquake of April 2015. It was also used during Hurricane Patricia later that year. 

On November 13th, 2015 the feature was used for the first time in a non-natural disaster, in the wake of the Paris terrorist attacks. It was also used in Brussels following reports of explosions at an airport and train station in the city.