Firefighters are trying to figure out what started a fire on Saturday that led to a massive plume of smoke over San Jose.SAN JOSE, Calif. (KGO) -- Firefighters are trying to figure out what started a fire on Saturday that led to a massive plume of smoke over San Jose.The fire happened around 7:45 a.m. on Stone Avenue just off Highway 87 in South San Jose.Video in the media player above is from a previous reportIt happened at a scrap metal yard.Firefighters tell us no one was hurt and no buildings were burned. Report a correction or typo