IT JUST HAPPENED RIGHT UNDER MY nose, in a split second," says Joanne Taylor. Moments before, her 18-month-old son, Grant Taylor Huff, had been playing with a cousin in the backyard of his maternal grandparents' cliff side home in Leucadia, Calif., near San Diego, while his mom and grandma chatted inside. Then his 4-year-old cousin popped her head in. "I can't find Grant," she said. Taylor, 31 and separated from Grant's dad, searched the yard and then crawled over a 3½-foot-high safety wall onto a towering bluff over the Pacific. Peering 80 feet below into the shallow surf on Stepping Stones Beach, she saw a lone fisherman pointing down the beach. "I was just frantic," says Taylor, who rushed to stairs leading down to the ocean.

As luck had it, Jim and Maria Lindsay were walking their two Siberian huskies along the beach. Maria, 32, an occupational therapist, saw something crash into the surf and realized with a shock that it was a toddler. "He was trying to lift his head, and waves were pulling him down," says Jim, 39, an investment adviser. Jim grabbed the child, gave him to Maria to cradle and dashed to phone 911. When Taylor arrived, paramedics were already treating the boy.

Grant—who had apparently climbed over a fence into the yard of a neighbor with no safety wall—suffered only minor bruises, probably because babies' bones are so elastic, a Quality one emergency-room staffer calls P.B.F.—Positive Bounce Factor. Indeed, Grant easily bounced back to his regular routine of Sesame Street and playing on his scooter. Will he be visiting his grandparents soon? "Not," says his mom, "until they put up a new fence."