Atlanta homeowner Eric Hickman says he had no idea his backyard wood deck was rotting away until it buckled to the ground as he grilled burgers during his 12-year-old daughter's birthday party last year over Memorial Day weekend.

The girl escaped injury, but watched the hot barbecue grill land on top of her 70-year-old grandfather when he, her father, and an uncle wound up under the fallen deck. The grandfather suffered third-degree burns, and both sons had broken bones.

The 25-year-old deck gave way with no warning. The culprit wasn't the deck's age, although experts estimate a deck's lifespan is closer to 15 years. The problems: improper flashing and inadequate fasteners.

An 84-year-old University Place, Wash., grandfather didn't fare as well three years earlier when a second-story house deck collapsed during a party for his grandson, who had just enlisted in the Navy.

Sixteen people gathered on the nine-year-old deck, which rocked away from the house, killing the man and injuring seven others severely enough to send them to the hospital.

The cause: The deck was nailed rather than bolted to the side of the house.

One study blames sudden deck collapses for 33 deaths and 1,122 injuries between January 2000 and December 2006. Another calculates 17 deaths and 350 injuries in the past five years.

The most tragic incident, in Chicago in 2003, killed 13 people—most of them crushed when the third–story porch fell on them—and injured 57.

And those are just the reported incidents, says Michael Morse, founder and president of DeckLok, a manufacturer of deck fastening systems, who estimates that a deck a week buckles to the ground, but isn't reported unless someone gets hurt.

Case in point: Contractor Todd Funfar, president of Fargo, N.D.–based Deck Masters, evaluated more than 80 collapsed decks during the particularly snowy winter of 1996. None involved people; none was reported to building or fire authorities.

Reported or not, such tragedies are bound to increase. Morse, who studied six years of reported deck failures, estimates that deck collapses are increasing at a rate of 21 percent a year. Building officials point the finger at do–it–yourselfers and inexperienced handymen who don't bother with code inspections. But when a deck comes tumbling down, it reflects as much on the deck industry—including professional home and deck builders and manufacturers of deck fasteners—as on the homeowner or handyman.

Some deck collapses prompt back–and–forth lawsuits that blame everyone from the home builder to the subcontractor who built the deck to the manufacturer who made the hardware to the party guests who danced on the deck minutes before the tragedy. In fact, each one has a responsibility to ensure a sturdy deck and the safety of the people who use it.

"When a deck falls down, it puts a black eye on the whole industry," says Kim Katwijk, owner of Deck Builders in Olympia, Wash., and a director of the North American Deck and Railing Association.