Residents living in some La Habra condominiums woke up Thursday to find a massive sinkhole opened between two complexes overnight.
Officials responded to the 900 block of West Imperial Highway about 10:45 p.m. Wednesday, La Habra police said in a news release.
Investigators believe the neatly manicured and tree-lined property fell into a collapsed underground flood control channel between two rows of condos. Officials suspect ground saturated by recent rains may have played a role.
The sinkhole runs about 80 to 100 feet long and 20 feet wide, according to police.
One resident of the complex, Ernie Cabrera, was walking his dog Wednesday night when the enormous pit suddenly opened up. He said he heard a "big ol' rumble, saw the trees sway, and then they just started falling."
"But it was a big explosion, almost like if lightening hit," Cabrera told KTLA.
Others awoke to the shock of a drastically changed landscape outside their home.
"It was just crazy. It was completely unbelievable," Jennifer David said. "It's weird to just wake up and you have a giant sinkhole in your complex."
One nearby condominium was damaged by a tree that fell into the nearly 15-foot deep hole, but no injuries have been reported.
Building inspectors responded to the site and were continuing to assess the damage. So far, residents have been told they can stay in their homes but can't use their front yards.
It wasn't immediately clear how the situation would be repaired.
Shannon Widor with Orange County Public Works said officials were working to determine who owns the land involved before they could make further plans.
The flood channel might be private property, he said, but it does connect with county facility across the street.
"At this time we're still assessing, working with the city to identify who owns the flood channel," Widor said. "It did collapse underground here, and we'll assess next steps."
KTLA's Erika Martin contributed to this report.