The woman, 81, was there for about seven hours before a relative came to help, Pioneer Press said.
The woman answered her door before 8 o'clock to a man who said her neighbor was being robbed. As she went to call the cops, he broke a window, forced his was in and began to demand money.
After she gave him what money was in her purse, he took her upstairs to her bedroom where he tied her hands and ankles while he ransacked her house, the woman told police.
Before the robber left he called 911, giving them the wrong address.
The suspect was described as a "chubby" build, black man in his 30s.
Police are wondering if the suspect is connected to the robbery of an 82-year-old man's house on Oct. 29, which was done in the same fashion.