Firefighters rescued a woman from a deep hole after she was trapped inside it overnight in Midwest City, Oklahoma, authorities said.

The 32-year-old woman was out for a walk near Northeast 23rd Street and Saint Luke Avenue late Tuesday night when she fell headfirst into the unmarked hole, The News & Observer reported Thursday.

The hole was about 2 feet wide and 8-9 feet deep, Midwest City Fire Major David Richardson was cited as saying by the outlet.

"Our technical rescue crews were able to lasso a rope essentially around her and pull her up out of the hole," Richardson said, according to KOCO-TV.

It wasn't until Wednesday noon when a couple heard the woman shouting for help while they were walking along the street, Richardson added. The woman, whose identity was not revealed by authorities, said she screamed for several hours before the couple helped her.

After making contact with her down the hole, they called 911 with the help of another passerby.

"A couple was walking along the street, and they heard a woman yelling. Whenever they looked down the hole, they made contact with her," the official added, according to local news.

Authorities believe the woman was trapped in the hole for eight to 12 hours before she was pulled out by Midwest City Fire's technical rescue crews. She suffered bruises and scrapes in the incident but no immediate external injuries, cops said.

The woman was taken to a hospital in stable condition for a complete medical evaluation. Officials said that she managed to stay warm in the hole during the night, thanks to being dressed appropriately according to the freezing weather conditions in the vicinity.

Meanwhile, city officials were looking into the circumstances that resulted in the formation of the hole and why it was unmarked. The rescue team found a curve within the hole, "almost like a slight 'J,' Richardson said. It was immediately filled.

"It's a very odd situation to have a hole in the ground like that. We're trying to bring out multiple city crews out here at this time to figure out where the hole came from, is it a sinkhole, was it a contractor that drilled for a purpose. We don't know why the holes there," he added.

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