MODESTO (CBS SF) — An elderly woman and her son are in critical condition, after a pack of pit bulls managed to get inside their Modesto home and go on the attack Tuesday.

Sheriff’s deputies said they found three of the four pit bulls viciously mauling a man in the backyard of the home on Glenn Avenue, and the fourth dog circling the victim.  They also found an 85-year-old woman inside who was severely injured.

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Both victims were transported to a local hospital in critical condition.

Deputies said they shot two of the dogs, while two others ran off.

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“It sounded like just dogs were fighting…it just didn’t sound right,” said Celeste Vaughan, who heard the attack.

Stanislaus County Sheriff Adam Christianson said, “We’ve seen bites involving pit bulls before. But never four dogs on a single human being to the point that the victim in this case was unconscious and unresponsive.”

When deputies tried to catch the other two dogs, the pit bulls attacked and the deputies shot them.

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Investigators are trying to track down the dogs’ owners.