Trees Found Not Guilty of Arson in LA Fires

Everyone spent the last year blaming the trees.

After the 2025 Altadena and Pacific Palisades fires burned through 37,000 acres (about 150 square kilometers) and destroyed more than 16,000 structures, the cleanup crews came through and took the trees too. Scorched, suspicious, a liability. Out they went.

Then UC Davis researchers went back and actually looked at how the fires moved. The picture is almost exactly backwards from what people assumed.

The fire spread from houses to trees. Not the other way around.

Wood-frame construction, cars and fences were the ignition points. Trees in the path caught what the structures threw at them. Which means the post-fire tree removal campaigns that stripped Altadena's streets in the name of fire safety were, in many cases, removing the wrong things.

Researchers used lidar to map the damage in 3D, comparing before and after. Altadena lost about 30 percent of its public trees. Some fell to fire. Others went to crews who didn't wait to see whether they might survive. Arborists say it takes a full growing season to know. One oak that everyone assumed was dead started leafing out in March.

The data is now being used to inform what Los Angeles replants and how it rebuilds.

Read the full story at UC Davis, May 26, 2026

Hot Take: Turned out the solution to the fire problem was building codes, not chainsaws. The trees were just standing there.