Danger Lurking Under The Backyard?

Gerri Carter of Allentown, N.J., never thought twice about letting her two-year-old son play in the backyard. Until one afternoon little James vanished. He just disappeared.

"He just fell right through," Carter tells CBS News correspondent Mika Brzezinski.

As photos show, the ground under James had literally caved in. He had fallen into an abandoned cesspool.

"It was just mud, water. . . he was up to his chin," Carter says.

And she couldn't get to her son.

"I couldn't reach his head," Carter says. "He was just looking up screaming hysterically."

Experts say millions of homes have these abandoned tanks under their yards. Before neighborhoods had sewage lines, every home had its own cesspool. But their concrete covers were not made to last forever.

Jim vonMeier, a safety consultant for the septic industry, says, "Concrete after 30, 40, 50 years starts to weaken and cave in. . . especially the type of concrete used in those days."

So we are hitting high time for these things to pop?

"Yes, this is going to become a very common occurrence all over the country now," vonMeier says.

Cesspool collapses have already made headlines across the nation. In New Jersey, a 92-year-old-woman died after plunging 15 feet down into a cesspool behind her house.

In Texas, a two-year-old girl was killed after an abandoned tank at her home caved in.

In all cases, the homeowners had no idea the holes even existed.

So how do you find out if your house has one of these hazards?

"You have to look at the records. If your house was built in 1953, but the sewer line didn't come in until 1965, you know you've got one in your yard," says vonMeier.

Little James survived without a scratch. But Gerri has a message for homeowners: Find out whether your home has a cesspool, and whether or not it was filled in.

"Those people who say it's never going to happen to us, our yard is fine," she says. "No, you don't know."