Update: 'Mythbusters' Says 'Safety Protocol Followed' on Set That Shot Cannonball Into a Dublin Neighborhood

A cannonball that was misfired during the filming of an episode of  "Mythbusters" struck a Dublin Ranch home Tuesday afternoon then careened across a busy road and ended up inside a van parked in a driveway.

Amazingly, no one was hurt in the 4:15 p.m. incident during which a 5.5-inch projectile struck a two-story home on Cassata off of Old Westbury Way near Tassajara Road in east Dublin.

Apparently, the cannonball went through the house while the occupants were asleep, then exited the structure and bounced across Tassajara and into a parked car, breaking its glass and landing inside the vehicle.

The Alameda County Sheriff's Department is investigating the incident and has shut down the bomb range in the meantime.

The department's bomb squad often works with the popular Discovery Channel show because its creators are based in the Bay Area and often film in the East Bay.

The show was using a cannon it had built about two years ago and had used multiple times, said Sheriff's spokesman J.D. Nelson, who regularly assists the production. The cannonball was supposed to go through barrels of water and through a cinder block wall, but instead, due to a "misfire," it went over the barrels, struck a hill and bounced off the range.

"It took a very unfortunate bounce that sent the ball skyward and out of the range," Nelson told media at the scene Tuesday evening.

He said it was a case of "tremendous bad luck" that ended up being "tremendous good luck" because there were no injuries.

Nelson said the three occupants of the home, including one child, slept through the cannonball strike but were awoken by dust from the aftermath settling onto their faces.

Dublin resident Jasbir Gill, who lives at the corner of Springvale and Bellavue, said the cannonball landed inside his mini-van. He said he was inside the house  at the time but had been in the van with his kids just five to 10 minutes earlier.

"I thought it was only a window, but I looked inside and the whole dash was smashed," said Gill. "It's scary."

The Sheriff's Department's shooting range and bomb squad training facility is used often by "Mythbusters," said Livermore Patch columnist Susan Young, an entertainment writer familiar with the show, which is known for concocting strange experiments to test wacky theories.

Nelson said the television show has used the county's bomb range more than 50 times for experiments and filming.

"We never even had any kind of an incident let alone anything this terrible," Nelson said.

Discovery Channel and Beyond Productions emailed Young the following statement:

On Tuesday, December 6, 2011, MythBusters, produced for Discovery Channel by Beyond Productions, was filming on a closed set at the Alameda County Sheriff’s Department bomb range in Alameda County, California. During the testing, a cannonball took an unforeseen bounce from a safety berm. No injuries were reported, but damage was reported in one Dublin home and one parked car.  Sgt. J.D. Nelson, Public Information Officer and bomb technician for the Alameda County Sheriff’s office, who is a regular safety explosives expert for MythBusters, was on site and all proper safety protocol was observed. Beyond Productions is currently assessing the situation and working with those whose property was affected.

Nelson said the TV crew responded by sending a senior producer to the affected residents and arranged to meet with their insurers.

"They (the 'MythBusters' crew) are insured for these kinds of things," he said.

— Bay City News service contributed to this report.