WEST VALLEY CITY — A woman who police say was chained to an engine block by her boyfriend so she wouldn't leave their apartment was rescued late last week thanks to a neighboring good Samaritan. Her boyfriend was located and arrested Tuesday.

Details of the bizarre incident were released Wednesday by police.

Investigators believe the woman was held captive in her apartment, near 2900 West and 3500 South, for several days, possibly a week or more. When her boyfriend was home, she was allowed to roam freely in the apartment. But when he left, a chain was tied around her ankles, said West Valley police Capt. Tom McLachlan. The other end of the 20-foot dog chain was tied to a 6-cylinder engine in the closet, he said.

The chain was long enough for her to reach a restroom, but she could not leave the room. The door leading into the room had deadbolts on both sides, McLachlan said, and both were locked. The windows in the room were screwed shut so they couldn't be opened. Additionally, the apartment had no phone.

Last Friday morning, the desperate woman wrote "call 911" in the condensation on her window. The first floor window, which was in the back of the building, faced a neighboring trailer court. The nearest trailer was about 20 yards away.

Peter Erkelens, 32, who lives in that trailer, was just getting home from work when he saw the woman writing on her window with her finger, he said. He saw the message and was able to talk to the chained woman through the glass. He then called 911 using his mobile phone.

"She can't come out of the room," Erkelens told the dispatcher in the taped emergency call released Wednesday. On it, Erkelens can be heard talking to the woman in the background while also talking to the dispatcher.

"She says her boyfriend/husband is going to hit her if she comes out of the room. She says he's been hitting her all night," he said.

The woman talked to the man while her boyfriend was still in the house, McLachlan said. She barricaded the door with a dresser so he could not get in, he said.

When police arrived, they kicked in the front door of the apartment and broke out the glass from the back room. They found "a frantic woman crying," according to a Salt Lake County Jail report.

"After police told me she was chained to an engine block, I was kinda shocked and disgusted," Erkelens said. "Who does that?"

The woman told officers that her boyfriend, "beats her regularly, strangles her and doesn't let her leave." In addition to the engine block and chain, police also found padlocks and the two-way deadbolt lock "that was secured with a key from the inside and outside."