By Alex Fitzpatrick and Arpita Aneja
During the recent attacks in Paris, Facebook activated a feature that let people in the city let their friends and family know they were safe. Called “Safety Check,” the feature grew out of a project created after the devastating earthquake and tsunami that struck Japan back in 2011.
For everything you need to know about Facebook’s Safety Check, watch the Tech Time video above.
More Must-Reads From TIME
- Why We're Spending So Much Money Now
- The Fight to Free Evan Gershkovich
- Meet the 2024 Women of the Year
- John Kerry's Next Move
- The Quiet Work Trees Do for the Planet
- Breaker Sunny Choi Is Heading to Paris
- Column: The Internet Made Romantic Betrayal Even More Devastating
- Want Weekly Recs on What to Watch, Read, and More? Sign Up for Worth Your Time
Write to Arpita Aneja at arpita.aneja@time.com