By Karen Morfitt

DENVER (CBS4)– The director of the 911 service for Denver is responding to claims that a call for help went unanswered for more than 15 minutes.

Athena Butler says working out of a backup call center on Sunday may have played a role in the delay.

The emergency call was made to report an armed robbery at the Lincoln Market in the Whittier neighborhood.

“When we work in that capacity the calls are first in first out there’s no priority given to 911 like it is in our primary center,” Butler said.

Michael Davanzo was working at the Whittier Café next door when the victims came looking for help.

“When we were in the back on hold with 911 he said that he had been on for about 17 minute or so,” Davanzo said.

Five people made calls to 911 to report the crime at the Lincoln Market and Butler says they will look into the wait times of each.

Initial information shows the first call to 911 came in at 7:02 and that caller waited four minutes before hanging up.

“Once they hung up and we had another person available that call dropped to them and so they tried to call that number back and when they called back they got their voicemail,” she said.

It wasn’t until 7:13 after a witness called the non-emergency number did information about what happened— make it into the system and police were dispatched.

Butler says from an increase in cell phone use, to rapid population growth in Denver there are a number of factors call takers now have to adjust to.

“We’re trying to mitigate anyone being on hold, which is nearly impossible these days. We have the support of the city to take additional steps. One by getting in our new building in 2018 which will be much larger and allow us to hire more people,” Butler said.

Davanzo is just hoping something is done soon, “When you’ve got lives on the line and you’re goal or your purpose for being there is to make sure people get help in a timely manner it’s not really something you can excuse.”

Butler says they were using the backup while the primary center was getting an upgrade, which does not happen often.

The system is not only less efficient but they also cannot have as many employees taking calls.

Butler says what happened on Sunday is not the norm. She also said that in January, 94 percent of all the calls they took were answered in 40 seconds or less.

Karen Morfitt joined the CBS4 team as a reporter in 2013. She covers a variety of stories in and around the Denver metro area. Connect with her on Facebook, follow her on Twitter @karenmorfitt or email her tips.