Fire crews battled flames overnight, and on Thursday morning, the spread of the blaze, named the Thompson Fire, remained relatively stable, at around 3,700 acres burned.
The fire was reported to the San Jose Police Department at 8:24am Saturday in dry vegetation just inside the San Jose city limits near Meadowlands Lane and Wild Meadow Way.
About the same time and the same location as the 35-acre Silicon Fire, PG&E responded to a report that metallic balloons had come into contact with transmission lines.