Complex sentence: A lahar can bulldoze through virtually any structure in its path, but quickly loses force when it leaves the channel of its flow: even frail huts may remain standing while being buried up to the roof with mud.
Split into simpler sentences: A lahar can bulldoze through virtually any structure in its path. A Lahar quickly loses force when it leaves the channel of its flow: even frail huts may remain standing while being buried up to the roof with mud.