That's why, in a multi-story building with landings, if you find yourself stuck behind a barely-ambulatory butterbarge, you wait until you're about 4-5 steps from a landing and nobody's in front of it, grab the railings with both hands, propel yourself forward and plant both feet between the shoulder blades, kicking straight out. When your feet connect, it'll likely stop your forward momentum and you can safely plant your feet on the staircase, continuing forward progress. The distance to the landing coupled with the force of impact should keep it down long enough(if it ever gets back up) for the congestion of humans to pass by it on the extra space afforded by the landing. If it's a literal life or death scenario, a fire, you probably just saved several lives. Don't feel guilty.