Around 6 to 18 years ago, I stumbled on a movie while browsing the TV. I think I stumbled on the movie in the middle of the plot.
A group of people were stuck in what looked like an underground laboratory, with a dragon wandering around. The dragon was possibly created there.
The dragon aside, the movie was pretty much non-scifi.
They spent most of their time locked in a room where they felt safe, though some of them where either brave or bold enough to get out and move to another room. I remember at least 3 of them leaving at first:
The two first persons were a man and a woman. They both went into the room of... I suppose one of the scientists. In that room, they found some information, including a fantasy book about knights and dragons. The man (who I believe is the main protagonist) also found a sword in that same room, and he decided to keep it (though he never used it to fight the beast). Then they came back to the main group.
The third person was... a heavy guy, if I remember correctly. He was tired to hiding, so he went for his bedroom. He turned on the air-conditioning and laid on his bed with a walkman, listening to some music. Unfortunately, as some people told him, the dragon was seeking cold atmosphere, since the entire laboratory was hot, and having turned on the air-conditioning, he brought the dragon to him. For an unknown reason, at some point, he picked up his baseball bat, cursed a bit to the door, then smashed the door panel, which opened the door. The dragon was right on the other side, and roasted him.
After these events, they decided to leave the underground laboratory. They went to an inactive elevator, where they started climbing up. At some point, the dragons found them, so one of the women volunteered to guard the elevator door with a hand gun while they were still climbing. In the end, only 2 people were left in the elevator: a man, and the former woman. Both were roasted by the dragon without a chance to fight back.
Those who managed to escape climbed into some form of rotorcraft or plane (maybe an army rotorcraft; it was big enough for people to stand inside). A short time later, the dragon somehow managed to get out of the underground laboratory and joined them into the dark sky of the night.
One of the surviving guys decided to open the rotorcraft's door to take pictures with his camera, but the craft got shaken and he fell. That guy was either one of the scientists, or one of the executives who worked in that underground. He was fascinated by dragons, so I expect he was one of the reasons that beast came to life.
One of the two guys piloting the craft called for back-up, and two of his friends came with fighter aircraft. One of them looked at the beast, and told him on the radio something in the line of:
Man, is it me or that thing is a dragon?
The dragon managed to blow up one of the aircraft, but the other managed to take down the beast.
A few things happened between that and the end of the movie. On the pretty end, they showed us a familiar room in the underground laboratory (where some characters went through at some point). The movie ended with the last pictures showing us what looked like eggs (probably the dragon's).
