Below a photo of the wreckage. They were flying VFR and possible cause was the fog in that area. The passage where they crashed is known as a difficult passage and fog/low clouds often close the passage. The pilots were not familier with the area.
http://www.hoy.es/20070613/nacional/...706131332.html
http://www.apythel.org/modules.php?n...ticle&sid=1066