Seaman who died from lack of oxygen were 'unaware of dangers'

Three seamen who died because of a lack of oxygen in a ship's compartment had failed to appreciate the possible dangers they faced, a report said. The men who were working to secure a rattling anchor chain in an enclosed space on the Viking Islay ship off the Yorkshire coast in 2007 failed to recognize the atmosphere would eventually become oxygen deficient.  According to a BBC article on the subject:
Marine Accident Investigation Branch experts recommended training changes. The marine accident experts added that the training and subsequent drills in the use of such devices "had not been sufficient to ensure the limitations of the equipment were recognised in an emergency".

And the document added: "The ship manager's company policy on entry into enclosed spaces was not clear and did not take into account scenarios that could require crews to enter confined spaces while at sea".

Gas monitoring equipment supplied to the vessel was unsuitable for ensuring safe entry into enclosed spaces, the experts concluded.

Tugboat, barges strike gas line causing deadly explosion in Louisiana

Lafayette, Louisiana's The Daily Advertiser reported that a tugboat carrying two barges struck and underwater gas pipeline causing a massive explosion that killed three seamen, severely burned another, and left three others missing.  The accident and explosion occurred in West Cote Blanche Bay near Cypremort Point, Louisiana.
The Daily Advertiser:

The tugboat, which belonged to Central Boat Rentals Inc. of Berwick and two barges, which belonged to Athena Construction of Morgan City, were carrying a tugboat driver, a crane operator and six crew hands, none of whom have been named.

Upon contact with the gas line, each of the vessels immediately were engulfed by flames. The tugboat and barge carrying the lumber detached and continued to burn as they drifted away. Crews on scene extinguished them first.

The other barge, roughly 1,000 or more yards away, remained over the gas line and burned for several hours before it was contained. Officials believe those missing may have remained on this barge in a hideaway below deck. It is unclear whether any of them could have survived the intense and prolonged heat.