DENVER -- Last August, The 7NEWS Investigators exposed problems causing 911 callers to sit on hold for several minutes and their emergencies going unanswered.

Now, The Investigators have uncovered 911 operators hanging up on callers, and a delay in responding to a crime in progress.

Is this an isolated breakdown or part of a larger trend? That's just one of the questions we are asking.

Denver police Chief Jerry Whitman has acted quickly, handing down discipline to three employees in the 911 call center. The message from the top: hanging up on callers is not acceptable.

"My heart was pumping. I was scared. I just -- everything -- I don't know. It was scary altogether," said Robert Sanchez (pictured, far left), the victim of a break-in.

A neighbor also dialed 911 to report what he witnessed: a crime in progress on his street in central Denver.

"She just hung the phone up on me. She didn't say bye. Didn't tell me nothing," said Ernesto Palomino (pictured, near left), a 911 caller. "(She) just hung the phone up on me."

Tony Kovaleski/7News: "What was your greatest fear that morning?"
Sanchez: "That this guy was going to get in and kill us."

According to police records, the first call came at 5:51 a.m., on Jan. 11.

"She tells me that she'll send somebody out. Ten minutes roll by. Nothing. Now the guy has already made his way into my basement and I'm on the phone again," said Sanchez.

In fact, police records show between 5:51 a.m. And 6:24 a.m., the two neighbors made a total of eight calls for help.

"She said there are a couple of homicides going on in the area, 'we'll get to you when we can,'" said Palomino.

Apparently there was not a single officer on duty in the city of Denver able to respond to the calls for help from these neighbors.

Palomino couldn't understand why help wasn't on the way.

"I'm thinking, 'What are you guys waiting for? These guys to commit another homicide until you come over here?'"

"Perhaps more disturbing than the delayed response was what happened next," Kovaleski said.

"She just hung the phone up on me," Palomino said. "She didn't say 'bye.' Didn't tell me anything. Just hung the phone up on me," said Palomino.

"I didn't get the service that I thought I was going to get when I called 911," said Sanchez. "And then to be hung up on. I didn't even know they were allowed to do that."

Denver city council member Doug Linkhart wants leaders inside city hall to take a closer look.

Kovaleski: "Is there a good excuse for hanging up on somebody calling 911?"
Linkhart: "no. No there's not. It should not take a half hour for police to be dispatched to a scene of a crime when a crime is in progress."

Denver Police Department records show a dispatcher did eventually send an officer to the neighborhood -- ultimately it took more than 30 minutes -- for a blue and white squad car to get the call to serve and protect.

Responding to our questions, Denver's police department launched an inquiry.

Kovaleski: "Did the events of that morning meet the expectations of the Denver police department?"
Lt. John Burbach/Denver Police Department: "No they did not. We're disappointed in our own performance."

Burbach said the department's review identified a communication breakdown, an unacceptable delay in dispatching, and an inappropriate decision to hang up on callers.

Kovaleski: "Acceptable?"
Burbach: "No. It's not acceptable. We teach all our officers, employees, calls takers, dispatchers alike to, you know, treat people as they want to be treated. And to take their concerns seriously. So, no it's not appropriate."

DPD said it has disciplined two call takers and a dispatcher, an action that may change the future, but never erase the memories of that morning.

"I mean, left helpless. I felt helpless. I didn't know what to do, and I was expecting a police officer to show up and help us, protect us," said Sanchez.

Whitman has decided not to release the tapes of the 911 calls and the hang-ups by the call takers at this time. He said the tapes are part of ongoing criminal prosecutions.

Despite the dispatch delay, police did arrest two men that morning for crimes in the neighborhood.

Is it an isolated breakdown or a trend?

If you have had problems with 911 in Denver or any city we want you to call our tipline number at (303) 832-tips. Provide us the details and we will investigate.