The helicopters were responding to a vegetation fire that spread from a nearby structure fire. One helicopter made a safe landing with no injuries, while all in the second helicopter were killed.
The iconic spindly plants are under threat from a variety of factors, including climate change and development, and the California legislature is stepping in to help.
Triple-digit temperatures are expected as energy officials warn the electrical load on Tuesday could reach the state's highest demand ever. Four deaths were reported as multiple wildfires burned.
Firefighters are proactively working to protect the giant trees by deploying a ground sprinkler system and clearing any materials that could fuel the fire.
David Scott Smith, 66, and Travis Shane Smith, 32, are accused of "reckless arson" in connection with the Caldor Fire, which burned more than 220,000 acres across three California counties this fall.
Another destructive fire season has Western states searching for ways to prevent it. The Southeast just might have the answers: setting controlled fires before the wildfires come.
Controlled burns help reduce wildfire risk by clearing out overgrown vegetation. The U.S. Forest Service is suspending them, concerning fire scientists.