HOUSTON -

A Southwest Airlines employee is under investigation for allegedly pulling a fire alarm at Hobby Airport, but there was no fire at all. On Tuesday afternoon police say charges in this case could be filed soon.

Houston police say in January, a Southwest Airlines employee was seen on security cameras laughing in a stairwell just seconds after the fire alarm had been pulled. Investigators say another employee was also there at the time. The airport was never evacuated, but all the doors were unlocked, which happens when an alarm is pulled. However, in this case because it was a false alarm, it was a breach in security.

Southwest Airlines said in a statement: "We're aware of an incident involving two of our Employees that was investigated by the Houston Airports System. We won't publicly discuss details of personnel matters but can confirm we cooperated in the City investigation and have concluded our own inquiry."

Since then the airport filed the most serious administrative grievance, which if upheld would have resulted in the permanent loss of the employees' security badges. But the employees involved appealed to a municipal court judge and penalties were reduced.

Meanwhile, at the same time, Houston police were actively trying to file criminal charges. Pulling a fire alarm when there is no fire could send someone to jail for up to a year.

But sources say the airport wasn't cooperating and no one would step forward to be the complainant -- that is until now.

Local 2 started asking questions and the general manager of Hobby Airport sent this statement: "The HAS team has already shown a willingness to view this matter in a very serious light and stands ready to assist should further action be deemed necessary by the appropriate authorities. If any delay has occurred in expressing this willingness, it was certainly not intentional and will be resolved as soon as possible."

Sources say charges could be filed in this case by the end of the week.

It's unclear why the fire alarm was pulled in the first place or if it was indeed done as a joke. Investigators say the reason they are pressing so hard in this case is also to send a message, that type of activity will not be tolerated, especially at an airport.