Earlier this month we reported on a sad incident on a French beach in which a horse and rider fell into decomposing green algae. Toxic gasses produced by the seaweed killed the horse almost immediately, while the rider was pulled to safety, narrowly avoiding the same fate. Read the story.  

At right, a photo of the horse, Sir Glitter, provided by his owner/rider.

Now an Associated Press report is adding quite a bit to the picture, including the hows and whys of the dangerous algae gas