Angry and frustrated families watched today as authorities began to tear down two of their broken homes and pour sand into a 90-foot-wide sinkhole just north of Dunedin, Fla.

"Of course I'm upset," homeowner Michael Dupre said. "I mean, there's our house."

The sinkhole, which started opening Thursday, swallowed one house and caused another to begin collapsing. At least six homes had to be evacuated.

Crews begin to demolish a home damaged by a sinkhole that opened up in Dunedin, Fla., Nov. 15, 2013. (Credit:Cliff McBride/The Tampa Tribune/Pool/AP Photo)

Experts said there were thousands of possible sinkholes waiting to open up under Florida homes. More than 250 have been reported since May 2012.

Related: Sinkhole swallows home

Dupre and other homeowners said they knew this could happen two years ago but were busy fighting with their insurance company to get the sinkhole fixed. He told ABC News that contractors hired by the insurance company were working at his home the past two days, pouring in grout to stabilize the home's foundation.

A few miles away in Weeki Wachee, Fla., Jimmy and Dee Etta Rowe Ferraro were having the same problem: A sinkhole is growing under their home. And they, too, were fighting their insurance company over how to fix it as they continued to live in danger.

"The whole place could go boom," said Dee Etta Rowe Ferraro. "It could happen right now as we sit with you. It could all cave into the ground and with us inside."

The ground underneath the Ferraros' home is already sinking in two places. In a report, an engineer said the house could "collapse." The Ferraros said they can't sell the house.

"Where do we go?" Jimmy Ferraro asked. "What do we do? This home was the biggest investment to make."

The Ferraros said they wanted the house protected with pylons that secure it deep into the ground. The insurance company only wants to fill the soil with a cementlike grout.

Photos: Sinkholes around the world

In March, a man was killed in his bed when a sinkhole opened up inside his house.

"We have a lot of retired people from up north who bring their savings and buy their home, and now they are thinking: 'Oh my goodness. I don't know what to do,'" said Taylor Yarkosky, a sinkhole contractor.

Families today raced to get work done. One resident put 19 trucks of cement into the ground.

"It's not a pretty sight," said Liz Marinelli of New Port Richie, Fla. "No one wants to have a sinkhole."