LOS ANGELES — When 2-year-old Samuel Zamudio’s grandmother came home and asked where the toddler was, family members frantically searched every room and even asked neighbors if they’d seen him.

Finally, the grandmother, 42-year-old Eustulia Zamudio, tried the backyard and screamed.

Lying in the dirt, his clothes torn from his body, was Samuel’s mangled, lifeless body. Police said the five pit bull mixes Zamudio kept out back had fatally mauled the boy.

“We just don’t have an explanation,” said Erica Vega, a family friend who was one of the adults at the house in Colton when the attack occurred. They said Samuel might have gotten into the yard through a back window. “He could have fallen down. The dogs just could have taken him.”

Colton police said the boy was “suffering from extensive wounds to the upper body” when he was rushed to Arrowhead Regional Medical Center, where he was pronounced dead about 6 p.m. Monday.

Witnesses said Samuel’s uncle, 23-year-old Marco Zamudio, tried to resuscitate him until paramedics arrived. Eustulia Zamudio alerted the family.

The two were arrested on suspicion of child endangerment resulting in death. Police said that Samuel’s uncle was responsible for the toddler, and that Eustulia Zamudio owned the dogs and the property where the attack occurred. They were due in court today.

The five dogs believed to be involved in the attack were being held at a San Bernardino animal shelter and will probably be euthanized, police said.