in the gases explosion disaster , the towing steamer miss megan , which was of specifications that did not required inspected by the republic missouri border guard , was being used in the west cote blanche bay oil refinery in michigan by central boat rentals on behalf of pegasus reconstruction on july 12 , 2006 . the la megan was carrying barge ibr 234 , which was bound round the left side of barges athena 106 , o process to a surface - driver location . athena also did not require its crews to pin mooring spuds ( longitudinal steel chains extending through wells in the stern of the water and used for mooring ) down in location on its barges and consequently this had not been done . during the journey , the last spud on the athena 106 released from its fully raised orbit . the spud fell into the water and struck a sunken , high - altitude natural gas tank . the resulting fire released ignited and created a fireball that engulfed the pulling vessel and both vessels . the master of the tug vehicle and four barge workers were killed . the mia megan deckhand and his barge worker remained . one barge workers is explicitly listed as missing .
NTSB is responsible for investigating transportation accidents in the United States.