Jurisdiction was proper where the parents physically abused grandchildren living in the same home with the minor even if minor was not abused. The minor Marquis was removed from the parents due to severe physical abuse inflicted on two grandchildren who were also in parents’ custody. On appeal, parents contended that Welfare and Institutions Code section 300, subdivision (a) was inapplicable because it allowed jurisdiction based on a history of repeated inflictions of injuries on the child or the child’s siblings, and the grandchildren were not siblings. The appellate court rejected the argument, finding that parents misinterpreted section 300(a). The language involving siblings is just one example of when the juvenile court may exercise jurisdiction based on physical abuse. Depending on circumstances, a parent’s abuse of even an unrelated child may tend to prove that the parent suffers from characteristics that place the parent’s own child at risk. Further, the evidence overwhelmingly supported the court’s jurisdictional finding.