Florida Land O
Florida Land O'Lakes sinkhole homes_00011006.jpg
Now playing
00:49
Homes destroyed by Florida sinkhole
PHOTO: CCTV
Now playing
00:57
Sinkhole kills 4 people in China
Florida Land O
Florida Land O'Lakes sinkhole homes_00011006.jpg
Now playing
00:49
Homes destroyed by Florida sinkhole
cars fall in california sinkhole nr vo_00001230.jpg
cars fall in california sinkhole nr vo_00001230.jpg
PHOTO: KTLA
Now playing
00:46
Watch: Car teeters over sinkhole edge
Texas deadly sinkhole _00000113.jpg
Texas deadly sinkhole _00000113.jpg
PHOTO: KABB
Now playing
00:45
Cop dies after huge sinkhole opens up
Sinkhole toxic drinking water Florida pkg_00000123.jpg
Sinkhole toxic drinking water Florida pkg_00000123.jpg
Now playing
01:22
Massive sinkhole threatens drinking water
china sinkhole opens on highway orig vstan bpb_00003623.jpg
china sinkhole opens on highway orig vstan bpb_00003623.jpg
Now playing
00:53
Giant sinkhole swallows busy intersection
china bus falls into hole vonat_00001005.jpg
china bus falls into hole vonat_00001005.jpg
PHOTO: Fengyuyifan
Now playing
00:28
Moving bus falls into sinkhole
A dog was buried alive in a Missouri sink hole.
A dog was buried alive in a Missouri sink hole.
PHOTO: Courtesy Lisa Van Valkenburgh
Now playing
01:20
Missing dog found in sinkhole
PHOTO: Kyle Rice
Now playing
00:50
Massive sinkhole stops traffic
Sinkhole Mississippi drone footage newday_00001426.jpg
Sinkhole Mississippi drone footage newday_00001426.jpg
PHOTO: Jason Hartwig
Now playing
00:52
Road rips open, 15 cars fall through
mississippi ihop sinkhole swallows cars dnt_00000425.jpg
mississippi ihop sinkhole swallows cars dnt_00000425.jpg
Now playing
00:59
Drain-pipe collapse causes 15 cars to fall through
australia queensland sinkhole cnni nr_00011917.jpg
australia queensland sinkhole cnni nr_00011917.jpg
PHOTO: Reuters
Now playing
01:35
Queensland sinkhole swallows campsite
China sinkhole bus stop ath_00001101.jpg
China sinkhole bus stop ath_00001101.jpg
PHOTO: v.163.com
Now playing
00:45
Sinkhole swallows 4 at bus stop
newday bus sinkhole brazil _00000601.jpg
newday bus sinkhole brazil _00000601.jpg
PHOTO: Reuters/TV Globo
Now playing
01:00
Bus washes away after collapsing in sinkhole
nr live sater collapsing yard evacuation _00005922.jpg
nr live sater collapsing yard evacuation _00005922.jpg
Now playing
02:02
Families told to evacuate as yard collapses

Story highlights

NEW: Five homes still unsafe to enter

NEW: Residents of four dwellings permitted to return

(CNN) —  

A sinkhole in Florida that swallowed two houses appears to have stopped expanding, meaning a recovery-and-repair operation can begin, authorities said.

Five homes in Land O’ Lakes, a residential area about 20 miles north of Tampa, are unsafe for entry, officials said Saturday. Residents of four dwellings were allowed to return.

It’s the largest sinkhole in Pasco County in at least three decades.

No injuries were reported. Officials said it will take weeks, perhaps months, for life to fully return to normal for residents in the neighborhood.

The sinkhole, estimated to be 225 feet in diameter and 50 feet deep, apparently began beneath a boat, which fell into the widening depression.

The active sinkhole is full of water and not draining because of debris, said Kevin Guthrie, Pasco County’s assistant administrator for public safety. It also looks like it’s full of household chemicals and septic tank parts.

“We’re treating this, in essence, as a hazmat incident,” he said.

“It is probably a good thing that this sinkhole has actually been stopped up,” he told reporters on Saturday. “There are a lot of contaminants in this water. It will allow us to decontaminate the area … and clear the debris out.”

A house starts falling Friday into a sinkhole in Land O
A house starts falling Friday into a sinkhole in Land O' Lakes, Florida.
PHOTO: WFTS

Authorities were called Friday morning about a depression the size of a small pool.

Fast-moving sinkhole

Pasco County Sheriff’s Deputy Jason Murphy said he arrived at 7:48 a.m. ET to find that a sinkhole had reached the corner of one house. Nobody was home, he said, but fire and rescue personnel were able to get two dogs out before a corner of the house fell into the sinkhole.

By that point, the sinkhole was growing quickly, with “large chunks of the ground actually caving in,” he said.

Murphy went to the second house and helped an elderly woman and two other females get out, he said. Other deputies yelled for them to move quickly because the ground was collapsing underneath a corner of the house, he said.

The residents of the first house drove up in time to see the rest of their house destroyed, Murphy said, speaking to reporters in front of the sinkholes.

“As soon as they got here, what you see now is what they witnessed as the house caved into the hole,” the deputy said. “They were unable to get any belongings. Everything they owned was in there.”

It may be weeks before streets near the sinkhole reopen, Land O
It may be weeks before streets near the sinkhole reopen, Land O' Lakes officials said.

Murphy and a resident of the second house managed to get back inside to retrieve medications and documents before the final collapse, he said.

The sinkhole, Murphy said, expanded quickly.

“You’re looking at about half an hour in time from (being) only a couple of feet across to taking up their entire yard to taking in part of the house and reaching over into the next house,” he said.

The sinkhole grew 25 feet to 30 feet per hour at first, then slowed to 10 feet per hour, Guthrie said.

People who live in some other houses at risk have removed some possessions and pets.

Sinkhole site spurs septic concerns

Authorities have not said what caused this sinkhole. Pasco County records show the houses were built on the site of a sinkhole, Guthrie said.

Sinkholes often 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 it, whether an open field, a road or a house.

Sinkholes are particularly common in Florida, which rests on a nearly unbroken bed of limestone, according to the Florida Sinkhole Research Institute. They often develop in Central Florida, including the Tampa area.

A sinkhole in Land O
A sinkhole in Land O' Lakes, Florida, swallowed two homes and forced the evacuation of nine others.

Deputies will be stationed in the neighborhood to protect residents and notify them of any problems, Sheriff Chris Nocco said Friday.

“For citizens, our hearts break for you,” he said. “We know there’s a high level of anxiety. … I know it’s going to be very hard for you to sleep tonight. Any bump in the night, you’re going to wonder what’s going on with your house.”

People were urged to stay away from the neighborhood. A fence will be built around the affected houses, and roads will be closed, Nocco said.

CNN’s Phil Gast contributed to this report.