When a fire broke out a few miles from his Altadena, California, home the evening of Jan. 7, 2025, Matt Blea and his family needed to make a crucial decision: Should they stay home, or evacuate? A friend who did mountain rescue told Blea to download a free app called Watch Duty. On the app, he could see the fire’s perimeter, track evacuation orders and read updates about the emergency response. “It influenced me to leave the home sooner than later,” said Blea, who left with his wife and son