It happened around 12:30 p.m. Tuesday off Cemetery Road in Arlington.

Police say four Jehovah's Witnesses parked in front of a house and as soon as one of them – a 70-year-old woman – got out of the vehicle, a pit bull attacked her.

“I just heard the screaming – I heard some screaming and I didn’t really pay much attention to it. I was on my phone and I just thought it was kids. It sounded like a little girl screaming,” said neighbor Bryant Christy.

He was horrified to learn that it was a woman screaming for help. Two people inside the house and the three people who had been inside the car did what they could.

Four of them were taken to a hospital; the most severely injured woman was rushed to Providence in Everett.

“It looks like the dog just escaped through the fence and was protecting its territory and we had very unfortunate results to that. The owner has done everything in terms of surrendering the animal to the police department; he even offered to do that,” said Kristin Banfield with the city of Arlington.

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Banfield says the owner went as far as to ask that the dog be immediately put down – and it was.

“He was genuinely concerned; he wanted to make sure the safety of his family and the public was protected,” she said.

“It was a good move on his part. What else can you do?” Christy said.

Neighbors say they have never seen the dog out, and police say they’ve never had any incidents with this owner or this dog. As of 5 p.m. Tuesday, there was no information available about the victims' condition.