DUBLIN, Calif. — One of the zany experiments staged by the "Mythbusters" television show nearly turned into a suburban tragedy Tuesday in Dublin when the crew fired a homemade cannon toward huge containers of water at the Alameda County Sheriff's Department bomb-disposal range.

The cantaloupe-sized cannonball missed the water, tore through a cinder-block wall, skipped off a hillside and flew some 700 yards east, right into the Tassajara Creek neighborhood, where children were returning home from school at 4:15 p.m., authorities said.

There, the 6-inch projectile bounced in front of a home on quiet Cassata Place, ripped through the front door, raced up the stairs and blasted through a bedroom, where a man, woman and child slept through it all — only awakening because of plaster dust.

The ball wasn't done bouncing.

It exited the house, leaving a perfectly round hole in the stucco, crossed six-lane Tassajara Road, took out several tiles from the roof of a home on Bellevue Circle and finally slammed into the Gill family's Toyota Sienna minivan in a driveway on Springvale Drive.

That's where Jasbir Gill, 42, who had pulled up 10 minutes earlier with his 13-year-old son, Manvir, found the ball on the floorboards, with glass everywhere and an obliterated dashboard.

"It's shocking — anything could have happened," Gill said after the van had been taken away as evidence, along with the cannonball.

Sgt. J.D. Nelson, a spokesman for the Alameda County Sheriff's Department who is also a consultant for the Discovery Channel TV show, said the television crew was "tremendously lucky that it didn't seriously injure or kill somebody."

Nelson said "Mythbusters," a show on the Discovery Channel, had used the bomb-disposal range without incident while shooting portions of more than 50 episodes over the past seven or eight years. The show does not pay a set fee but has donated to the department and given it exposure.

One of the terms of the deal, Nelson said, was that the show take out insurance in case of a mishap.

The show is based in San Francisco. Hosts Adam Savage and Jamie Hyneman use science experiments to confirm or debunk rumors or myths.

Reached Tuesday evening, Savage said, "I can't talk right now," before hanging up.

This isn't the first time projectiles in the area have hit homes. In 2007, a stray .223-caliber bullet, apparently fired during a training exercise at Camp Parks Army base in Dublin, shattered a window of a San Ramon home.