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A Dublin Police officer stands near the exit hole of a cannonball in the second story wall after it traveled through the home in Dublin, Calif., on Tuesday, Dec. 6, 2011. The cannonball was misfired during the taping of an episode of the Discovery Channel show MythBusters at the Alameda County Bomb Disposal Range. (Doug Duran/Staff)

A cannonball misfired by the "Mythbusters" TV show crew blasted through an East Dublin home Tuesday afternoon while its occupants were asleep. It then smashed through a window of a minivan parked a few hundred feet away.

No one was injured, and the home's residents did not wake up until the dust was settling on top of them, said an Alameda County Sheriff's Office spokesman.

The cannon was shot at the Sheriff's Office bomb range behind Santa Rita Jail about 4:15 p.m., said the spokesman, J.D. Nelson, who is also a consultant for the Discovery Channel TV show. He had been at the site with show producers all day, he said, though he said he was not by the cannon when it fired.

Producers have used that cannon -- which they built -- at the range more than 50 times without incident, Nelson said.

Tuesday was different.

The cannonball was supposed to go through a few water-filled barrels and a concrete wall. Instead, it passed over the barrels, through the wall, and then took a "very unfortunate bounce that sent the ball skyward," Nelson said.

About 700 feet away, it bounced in front of a home on Cassata Place, then tore upward through the home's front door and out midway up the back wall of the two-story house. Light could be seen shining through a round, cantaloupe-sized hole from inside the house out to Tassajara Road.

The cannonball then bounced at least once more, crossing the four-lane Tassajara Road, before smashing the window and dashboard of the minivan. It came to rest inside the vehicle, parked in a driveway at Bellevue Circle and Springvale Road.

"We had some tremendous bad luck and some tremendous good luck" in that no one was hurt, Nelson said.

Jasbir Gill owns the minivan; he and his children had just arrived home.

"It's scary," Gill said. "I was in the van five minutes before this happened." His home is on the east side of Tassajara.

He said he would like the show's producers to fix his car and to apologize for the damage.

"Mythbusters," which is produced for Discovery Channel by Beyond Productions, issued a statement through publicist Katherine Nelson late Tuesday that said the production company "is currently assessing the situation and working with those whose property was affected."

Sheriff's Office spokesman J.D. Nelson said he did not know the exact size, speed or weight of the cannonball. The bomb range has been closed pending an investigation, he said.

It's not the first time a home in the area has been hit by stray fire.

In summer 2007, an errant bullet blasted a baseball-sized hole in a San Ramon home from the nearby Camp Parks firing range, leading to an FBI investigation.

Camp Parks is the home of the U.S. Army's 91st Division, and is a training facility for more than 11,000 reservists. Calls to Camp Parks on Tuesday night went unanswered.

Staff writer Rick Hurd contributed to this report. Contact Paul Thissen at 925-847-2122. Follow him at Twitter.com/pthissen.

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