On April 11, 1991, an explosion on the M/C Haven resulted in a fire and the release of approximately 145,500 metric tons (t) of heavy Iranian crude oil near Genoa, Italy, in the industrialized coastal region of the northern Ligurian Sea. Approximately 30,000 t of cargo oil was released to the sea, of which only one-tenth reached the shoreline beaches along the Italian Riviera. An environmental assessment of the affected region indicated injury from the spilled oil to subtidal Posidonia/Cymodocea (seagrass) beds and the deep-sea benthic community and associated commercial fisheries. This was one of the first oil spills in which it was documented that oiled, shallow subtidal sediments (<10 m) were efficiently cleaned and large amounts of residual oil reached the deep sea bottom (100 to 400 m) as a result of burning cargo.