A series of strong storms is bearing down on San Diego, spurring concerns about flooding and falling trees.
Just last week, there was tragedy in Fallbrook when an oak tree toppled, crushing a mini-van and killing the driver.
Last year, a massive oak fell in Pacific Beach, killing a woman who was driving by.
Such incidents are rare but terribly frightening. And we usually worry about eucalyptus trees more than oaks or other trees.
But arborist Butch Everett tells us differently.
"Most of the issues with eucalyptus trees are large limb failures; most catastrophic failures are pine trees," Everett said.
The root system is to blame when the entire tree comes down.
"We always see pine trees with gurgling roots, growing in circles and basically choking off the stem of the tree, which causes it to topple," Everett said.
Our weather history is the reason we should be concerned as the next storms approach. Many trees aren't as stable as they had been.
"Over the last five years we've had little rainfall, annually about 11 to 13 inches and had a lot of root die back," Everett said.
And without a substantial root base that super-soaked earth can't always support the weight.
"What happens is we get drenching rains, the soil is very wet and winds come behind," Everett said.