A Pomeranian wearing a life vest slipped off a boat Sunday evening into the North Branch of the Chicago River and hasn't been seen since.
Tank, a yellow Pomeranian, went missing around 6:30 p.m. near Goose Island.
The 5-year-old dog's owners, Linn and Mark Lewis of St. Charles, searched for hours, working with Chicago Police and the U.S. Coast Guard to try and find the missing dog.
The couple had been boating in Lake Michigan Sunday for the Memorial Day holiday and entered the Chicago River around 6 p.m. They did not see him go into the water.
Tank weighs about 9 pounds and was wearing a yellow life vest with the word "Gladiator" written on the side.
"We always take him," said Linn Lewis, noting the dog knows how to swim. "He loves to go boating, we've taken him boating for years."
The couple hopes Tank swam to shore. Anyone who spots the dog in the area of Goose Island or Montrose is asked to call Chicago Police