"Stupid! AhhhH~" Diaz was the only one who had trouble going down the stairs as her weapon was way too heavy and she tried her best not to step on the unconscious soldiers. It was to the point that Tellie who was behind her had decided to grab hold of the metal ammunition backpack and aid her down the stairs.
Eventually, they caught up with Jin and the rest of the Grey Bears who did move away once they opened the doors of the basement. They thought that the squad were waiting for them because it was better to move in formation but then when they saw what the rest had seen, they too were standing still for a moment.
There was not just one or two Mecha Fire Dragons in development. There were rows of Mecha Fire Dragons in production. Six were in some holding bay while the seventh holding bay was empty even though the eighth had already been filled. But what made them hold their breath was the one at the very end of the basement floor.