The firewagons race through the streets of Dublin, and the crowds follow, only to be held back by the police in this Lumiere actuality, #711 in their catalogue.
I've commented in other reviews of various fire departments racing to various fires, that these scenes were usually carefully staged and not at all real; a Lumiere camera in 1897 was not the size of a mobile telephone. It was a huge, bulky item, so large that if you wished to moving it during a shoot, you had to put it on a railroad, or at least a wagon. So this was probably staged.
In which case, we need to consider that this is less about the fire -- which, if it's taking place at all, is outside the camera frame -- and more about the crowd of men and boys who rush from offscreen to gather at the left edge of the frame to observe the fire. Nowadays, that would be left to the assistant directors to handle. Back then, there was the cameraman, and the director. And the cameraman was busy dealing with the camera.