(CNN) -- The owner of three pit bulls that killed a 2-year-old boy Thursday has been charged in connection with the child's death, authorities in California said. Steven Hayashi, 52, was arrested on charges of child endangerment and possessing a mischievous animal that causes death or great bodily injury, the Concord Police Department said in a statement. He is being held on $120,000 bail. The dogs mauled the boy after he walked into the garage where they were being kept, police said. Authorities said the toddler was the suspect's step-grandchild. Two adult relatives and a young sibling were also home at the time of the attack, which police said occurred just after 8:45 a.m. Thursday (11:45 a.m. ET). The boy was taken to a local hospital, where he was pronounced dead. Police said they were still investigating the incident.
Police say three dogs mauled the 2-year-old . Authorities say the victim was the dog owner's step-grandchild . Hayashi is accused of child endangerment and possessing a mischievous animal .