get blocked off there simply could be no way for first responders to rescue them if they needed it. that is the risk that they are taking. separate is another concern and that is at the top of this volcano. that is that crater. the concern is if the crater gets blocked with rocks and boulders falling into it that could create pressure which may ultimately end up with an explosion. this explosion wouldn't be like the explosion you are seeing here. it could send boulders the size of cars flying into the air some half a mile. smaller rocks flying further than that. this could come within days or weeks or might not come at all. for that reason hawaii volcanos national park is closed. as for the 2,000 evacueeatize is anyone's guess when it will calm down enough. >> the bigger question of air quality which i know has been a major concern for residents.