RIVERSIDE, Calif. (KABC) --A Riverside family is dealing with a mysterious, massive hole in their backyard.
No one is allowed in the pool, on the swings or the trampoline, and the dogs are only allowed in the front yard after a hole about 30 to 40 feet deep was discovered.
"Every back door is locked, they're not allowed to play back here anymore, that's how dangerous it is," Tasha Jenkins said.
The hole was found while the above ground pool was being drained and flooded the backyard. All of a sudden the ground gave way.
Riverside Public Utilities believes it may be an old cistern, an underground reservoir to collect rainwater that was very common in homes throughout the 19th century.
The home was built in 1905.
City workers inspected the hole Thursday and said the homeowner is responsible because it's not part of the sewage system.
"At least $1,500 worth of concrete to put to the bottom, so it fills out the bottom, because if we just put fill dirt in there, it won't solve the problem, it might just make it quicksand," Alec Damani, who also lives in the home, said.