Several aftershocks from Newport Beach earthquake

There have been several aftershocks from Thursday's magnitude 3.5 earthquake in the Newport Beach area.

The aftershocks have all been small, the largest being a magnitude 2.2 temblor Saturday in the Irvine area.

Officials are trying to determine if the Thursday quake may have played a factor in a tree falling onto a car in Costa Mesa, killing a woman.

Haeyoon Miller, 29, was killed when the trunk of the 50-foot eucalyptus tree slammed into the roof of her Hyundai Accent as she waited at 17th Street and Irvine Avenue on Thursday afternoon. The Orange County coroner's officer listed the cause of death as accidental blunt-force trauma.

Public safety officials and seismic and horticultural experts were investigating the accident but had only theories to work with, from moist soil to trimmed roots to last week's magnitude 3.5 earthquake in Newport Beach.

UC Irvine seismologist Lisa Grant Ludwig said the quake, which hit about 2:56 a.m. Thursday and was centered near Newport Beach, may have played a role, though there could have been other contributing factors.