A California couple found a huge sinkhole that swallowed their backyard pond. The Daily Mail reported that Mark Korb who lives at the home with his wife said that the hold drained the pond behind his home in just a matter of hours.

The pond was man made and Korb said to KITV.com that hole "looks like the moon." He said a few years ago it took him seven days to complete the pond and the sinkhole emptied the pond much faster than manually. "I would guess probably four to five hours for this whole area to drain," Korb said to KITV.com.

His home is near Dutch Ravine and now Korb is investigating how the sinkhole occurred. , Sierra College Professor of Geology Alex Amigo said to KITV.com that "There was such a lot of mining activity going on in this area in the past, that we never know when there was a man-made cavity underground."

Earlier this month a man in Florida fell into a sinkhole that opened up suddenly in his bedroom.

"I heard a loud crash, like a car coming through the house," the man's brother, Jeremy Bush, said to CNN affiliate WFTS. "I heard my brother screaming and I ran back there and tried going inside his room, but my old lady turned the light on and all I seen was this big hole, a real big hole, and all I saw was his mattress."

 Jeremy tried to save his brother Jeff Bush standing in the hole and digging with a shovel until police came and pulled Jeremy out as the floor was still collapsing.

"When he got there, there was no bedroom left," Hillsborough County Fire Rescue spokeswoman Jessica Damico said to The Los Angeles Times. "There was no furniture. All he saw was a piece of the mattress sticking up."

Jeremy and four other people escaped from the home but his brother may be dead after "monitoring equipment lowered by engineers detected no signs of life, said Jessica Damico, the Hillsborough County Fire Department spokeswoman," reported CNN at the time.

CNN reported that "many sinkholes form when acidic rainwater dissolves limestone or similar rock beneath the soil, leaving a large void that collapses when it's no longer able to support the weight of what's above, whether that be an open field, a road or a house. These are called "cover-collapse sinkholes," and it would appear this is what's happening in Florida, where the ground beneath the home suddenly gave way."