New southern California fires destroy homes and prompt evacuations – as it happened

Hillside fire sparked overnight about 60 miles east of Los Angeles, while the Ronald Reagan library has so far survived a close call with the Easy fire

12.16am GMT

That's it for me here in Oakland as I leave my post for the night. Thanks for sticking with me for another day of wildfire news. With any luck, winds should ease up overnight and into the weekend, allowing firefighters to get a handle on the more than a dozen fires that burned today.

Before I sign off, let's take a look back at the day and see where firefighters stand on some of the biggests wildfires:

11.42pm GMT

What it means to 'contain' a fire

As we tune into wildfire coverage, we often hear the word "contain," as in the percentage at which a fire is contained. But what does that mean? It means, roughly, that firefighters have a handle on the inferno. But it doesn't necessarily mean the fire has been extinguished. In fact, fires can burn long after firefighters have contained them.

In the firefighting world, containment means a certain level of control - specifically, how much of the fire's edge, or perimeter, firefighters believe they can stop from expanding. A natural barrier such as a river or creek can help. So can human interventions such as using a bulldozer to scrape the vegetation off a swath of land to deprive the fire of fuel it could use to grow.

That's why even when a fire is 100% contained, it can still be burning and firefighters stay to make sure it does not get out of control.

Firefighters often set up layers of defense called contingency lines some distance from the containment line. They will scrape the earth clean down to the dirt on ridge tops up to a mile away from a fire's edge to set up a position to make a future defensive stand. Meanwhile, they work their way closer to the fire, building layer after layer of additional defense by laying lines of fire retardant and using bulldozers, shovels, axes and chain saws to clear out vegetation...

After a fire reaches 100% containment - which can take months, depending on the weather conditions, the fire's size and the area's topography - crews work toward declaring the fire "controlled," McLean said.

When a fire is controlled, it's essentially out. Authorities will no longer assign crews to the blaze and will instead send a patrol out daily to ensure no scorched areas rekindle and start another fire.