(CBS) – Fifteen people have been arrested in raids on a heroin trafficking ring that grossed $15,000 a day at one spot on the South Side, Chicago Police and federal officials say.

Authorities dubbed the investigation “Operation Wheel of Fortune.”

It was nicknamed that way because the South Side-based drug location raked in a daily fortune, transacted through a phone the defendants themselves called the “Vanna White Line.”

“The Vanna White Line, over the course of a six-month period as set forth in the complaint, had about 193,000 calls to it,” says U.S. Attorney Zachary Fardon. “If you think about it, that is, if my math is right, about a thousand calls a day.”

Fardon says that suggests the scope of the demand for heroin — and the heroin problem in Chicago — is mind-numbing.

The investigation can be traced to the killing of a Chicago 3-1-1 operator gunned down just two blocks from police headquarters last year.

“The woman that was killed was killed in a fight over the drug spot. She was an innocent person going to buy a cup of coffee,” Anthony Riccio, chief of the Chicago Police Organized Crime Bureau, said.

Police say the 16-year-old accused of killing her was a low-level member of this gang.

Federal drug-enforcement officials say community members did their part, sending in letters with tips.

Authorities say the 15 arrested – six more are targeted but not yet in custody — are all mid- to higher-level heroin dealers.