HOUSTON -

The city of Houston is now disciplining some 911 call takers following a Local 2 investigation uncovered photographs that appeared to show operators sleeping on the job.

The pictures were posted on the social media site Instagram. City 911 policy says sleeping is forbidden, in addition to using cellphones on the call center floor.

"We do take these things seriously, it's not a joke," said Houston 911 Spokesman Joe Laud.

After our story, the city investigated five people. One employee received a warning because she told her superiors she was posing for the photo and not actually sleeping.

The most severe discipline went to three people for taking and posting photos online. The three are on a probation period and got a paid day off.

The city says the employees were supposed to spend that day thinking about what they did wrong and whether they wanted to come back and be good employees.

A fifth employee was accused of sleeping on the job, but she was cleared.

The city said it doesn't have enough proof to issue additional discipline. Officials cite a lack of video, for example.

"Those photos do not make sounds," Laud explained.

City Councilman Ed Gonzalez, chairman of Houston's Public Safety Committee, is responding to the Local 2 investigation.

"I think it definitely it raises concerns," Gonzalez said. "We are going to see lapses and situations which fortunately (Local 2) brought to our attention and we can pay more attention to training or discipline, better management. I feel confident citizens can feel confident with the 911 center we have."

Gonzalez says after our story, operators know they are being watched closely.