Both employees were on the clock, being paid by taxpayers, when the sexual liaisons occurred.
"This goes beyond the pale," said Denver City Councilman Charlie Brown when he reviewed the CBS4 investigation.
"This reflects poorly on every city employee. It reinforces the image… that many people have that they (city workers) don't have enough to do, that they're overpaid and underworked. In this case for the people who believe that it gives them ammunition to say 'see I told you so' and it hurts everybody. It's embarrassing to the city," said Brown.
The CBS4 investigation found that at least three times in 2009, the female DIA employee, who was supposed to be repairing 113 passenger bridges that go from the airport's concourses to aircraft, slipped away from her duties and used a city vehicle to travel to Fire Station #1 at DIA.
Once there, she and a 20-year veteran of the Denver Fire Department, who was also on duty, entered the DIA mobile command post for sex romps. They were apparently unaware that the high tech vehicle contains a motion activated camera that records everything that happens inside the vehicle.
Another DIA employee, doing routine work, discovered the x- rated videotape from July 5, 2009. It showed the pair undressing and engaging in sex from 3:15pm to 3:26pm.
That led to further investigation of the digital recording system which showed the pair engaging in sexual shenanigans in March and April of 2009.
"I think everyone is shocked," said airport spokesman Jeff Green. "It was certainly a shock for those who turned on the video and said 'hey whats been going on here?'."
When DIA learned of what happened, Green said both employees were immediately suspended.
"We took immediate action. We're not going to stand for that kind of behavior at the airport," said Green.
The Mobile Command Post is an emergency response vehicle that houses computers, communication uplinks and audio and video equipment. It's deployed to emergencies on DIA runways like aircraft crashes.
In reviewing the case, a city hearing officer wrote,"An inadvertent bump into one of the many computers, uplinks, or other sensitive equipment could turn off or change settings, delaying or making it difficult to reset the equipment to a ready position to respond to life-threatening emergencies."
Bruce Plotkin went on to write that the "use of the command vehicle could turn one of DIA's show pieces into an object of derision, and could diminish DIA's reputation as a world leader in airport operations."
"We need to look into who allowed this to happen, who allowed them to leave their positions," said Councilman Brown. "Did they sign out?" he asked. "Who's watching them? It's an embarrassment for the city, I would hope for them and for DIA."
DIA spokesman Green said employees are trusted to do their jobs and comply with airport rules. He said they can't be constantly followed to make sure they aren't "hooking up".
"These particular individuals, their actions are incredibly unacceptable," said Green. He said many airport employees work autonomously.
After the videotaped sexual hijinks came to light, the city fired the female DIA worker. She told city officials she "conceded she made a terrible mistake, exercised very poor judgment, and engaged in unprofessional behavior."
Two weeks later she appealed her dismissal claiming it was unwarranted, unjust and without good cause. She asked for reinstatement, back pay and benefits along with attorney's fees and other costs.
That appeal was rejected earlier this year. Contacted by CBS4, the woman said what happened was "a nightmare to me." But she said she was a good employee who had no previous disciplinary problems.
The Denver firefighter resigned last September in the face of termination. City officials say in his 20 years on the job, there were no other disciplinary problems.
Lt. Phil Champagne, a spokesman for the Denver Fire Department, declined to be interviewed on camera. He said the Mayor's Office, Manager of Safety and City Attorney's office asked him not to speak to CBS4 on camera.
By phone, Lt. Champagne said, "We don't think those actions and that incident endangered public safety in any fashion. The Denver Fire Department has a zero tolerance policy regarding that type of behavior. The employee was offered the opportunity to resign in lieu of termination. He resigned before he could have been fired. He would have been terminated, hands down."
"On one hand you want to laugh," said DIA spokesman Green, "but on another you're shocked and embarrassed."