now to the extraordinary images tonight the scare for visitors at Yellowstone National Park the very close call with the geys are raining down rock and debris here's ABC's mola Leni this is the stunning moment a geyser in Yellowstone National Park exploded today sending a black plume of steam and mud up to the sky and panicked tourists running from Falling Rock and debris no one was injured but Park officials surveyed the damage the boardwalk used by Park goers destroyed the area shut down to visitors it happened in biscuit Basin near the Black Diamond Pool about 2 miles from the Park's most famous geyser Old Faithful hydrothermal explosions are common in Yellowstone occurring when superheated water flashes to steam underground the geyser acting like a pressure cooker exploding geyser explosions like this can be triggered by earthquakes in this case there was no earthquake activity that might have triggered it so this is really related to the local plumbing system of this particular feature in biscuit Bas well David scientists at Yellowstone tell us that this was a random event without warning still they are investigating exactly what happened and what it might mean for the future of this area David the last time an explosion similar to this happened at Yellowstone's biscuit Basin was back in 2009 yeah that was really something to see mola thank you