What's Up With All the Eucalyptus Trees Falling?

A eucalyptus tree took a tumble in Corona Del Mar yesterday, hitting four cars and two homes, according to the Daily Pilot. Fortunately, no one was injured.Normally news of a falling tree is as hyperlocal as it gets. It's the sort of thing you might hear about at a neighborhood council meeting. But this latest development seems unsettling, since it's at least the fourth time falling eucalyptus trees have made news within a few weeks.
First, there was a Woodland Hills woman complaining about "killer" eucalyptus trees that had been dropping branches on her street. One of them smashed her Ford Focus a few years ago and she sued the city and got a small sum. The woman Darlene Corby says the city has refused to do any more trimming, which she feels is a deadly mistake.
Then — and most tragically — Haeyoon Miller was killed by a giant eucalyptus tree that smashed her car while she was waiting at a stoplight in Costa Mesa last month. Officials in Costa Mesa aren't sure why the tree fell, but they responded by removing 100 blue gum eucalyptus trees from the area.
A few weeks ago a eucalyptus tree took a tumble in Silver Lake, taking down powerlines. Fortunately no one was hurt in that incident, but the trees leaves brushed against the home of a resident.
And now there's news of the blue gum eucalyptus taking a tumble in Corona Del Mar. Again, experts aren't sure why.
None of us here are arborists, but we're still curious: what's up with all the eucalyptus trees falling?