The incident happened in the Main Street area around 8:30 a.m., according to the Anaheim Fire Department.
Two people were treated at the scene and released, while the third person who suffered serious injuries was taken to the hospital. That person's current condition is not known.
No further details were immediately available.
This comes amid strong winds howling through the region Monday.
"Damaging winds could blow down large objects such as trees and power lines. Power outages are possible," the National Weather Service advised. "Travel could be difficult, especially for drivers of high-profile vehicles."
A high-wind warning was issued from 6 p.m. Sunday to 10 a.m. Tuesday for the inland areas of Santa Ana, Anaheim, Garden Grove, Irvine, Orange, Fullerton and Mission Viejo.