A day after their errant 30-pound cannonball blew holes through a Dublin home and smashed a minivan window, the stars of the "MythBusters" TV show visited the families affected to apologize.

The cannon shot made for lively headlines around the world, but residents here have been left with questions, concerns and a few repairs.

On Wednesday afternoon, outside the damaged Cassata Place home, hosts Adam Savage and Jamie Hyneman promised to make repairs. They said their show won't use cannons at the Alameda County Sheriff Office's bomb range again. If a cannon is needed, they will head to less-populated areas in Gold Country.

Savage and Hyneman also took photos with the children in the family whose minivan was smashed at Bellevue Circle and Springvale Drive, across Tassajara Road and several hundred feet from the home that sustained damage.

"I can't imagine how angry I would be if this happened to me," Savage said. "We do nonstandard things all the time, and we've been doing them safely for nine years. ... This is the worst thing we can imagine happening."

The hosts aren't sure how the cannonball experiment went awry. They weren't present when the cannon was ignited; the experiment was being conducted by other cast members.

"We haven't figured out why the cannon was aimed slightly high," Savage said. "It's a wake-up call."

The episode they were working on aimed to determine whether a ball shot from a stone cannon could breach a castle wall. The misfired cannonball was a test shot, a 30-pound ball of iron or steel, Hyneman said.

After leaving the bomb range, "it bounced kind of like a bowling ball and went right through the house," Hyneman said.

They used the bomb range because they thought it was safe, he said. "It's in a rather deep little valley," Hyneman said. "It has relatively little impact on the surrounding areas, in theory."

Earlier in the day, the owner of the damaged house declined to give his name or comment beyond saying, "I'm just trying to get my house fixed."

His front door and back wall have been patched, but the damage is evident. When he opened the door, light shone through a round cannonball hole above a stairway.

Dawn Chirdon, who lives next door to the damaged house, was home when the ball breached the walls, about 700 yards from where it was fired. She thought a tree had fallen and said an angel must have been watching over the cul-de-sac, because no one was hurt.

"There's kids that play out here all the time," she said.

The bomb range has been closed during the investigation, said sheriff's spokesman J.D. Nelson. Other firing ranges at the site are still active, he said. More than 50 "MythBusters" episodes have been filmed at the county facility in East Dublin, including three that featured the cannon, Nelson said.

Nelson and the county are not paid for their services, he said. Instead, the show has contributed money and buildings to improve the training facilities. That arrangement will reviewed by the Sheriff's Office, he said.

Dublin officials have been in touch with the Sheriff's Office to discuss the incident and ensure nothing similar happens, Mayor Tim Sbranti said.

"I really do think it was somewhat of a freakish accident," Sbranti said. "Even one incident is one we just can't have."

Dublin police Lt. Herb Walters said the cannonball was taken as evidence.

Tuesday's cannon accident had nothing to do with Camp Parks, said Dan Gannod, public affairs officer for the base, a U.S. Army Reserve training area.

All base firing ranges have been closed since 2007, when a bullet hit a San Ramon house, he said.

James Prenton, who lives down the street from the damaged house, was surprised nearby firing ranges were active given that the Camp Parks ranges have been closed for years. He wants them all shut for good.

"I'm sure there will be another complaint," Prenton said.

Contact Paul Thissen at 925-847-2122. Follow him at Twitter.com/pthissen.