How Watch Duty became the go-to app for people fleeing the L.A. fires

Watch Duty has added 750,000 users in the last 12 hours, as L.A. residents rely on it for real-time information to track the wildfires around them.

Early on Wednesday morning, as the Eaton fire quickly grew northeast of Los Angeles, Jess Reynolds was glued to Watch Duty, a fire-tracking app on her phone. Reynolds, a photo editor at Fast Company who lives in the neighboring city of La Cañada Flintridge, hadn’t gotten an evacuation warning yet. But as the app gave detailed updates on the spread of the fire, she decided it was time to leave, pulling out of her driveway at 5:30 a.m. Hours later, her whole city was under a mandatory evacuation order.