Two local volunteer fire departments were among nine which responded to a Saturday afternoon blaze in Summitville that burned for six hours and could be seen for miles.Volunteers from Morrison and Viola fire departments helped to battle the blaze that consumed Tennessee Biodiesel on Shady Grove Road in Summitville.One employee received minor burns and area homes were briefly evacuated for fear the fire might cause a large-scale explosion. The fire erupted at 12:50 p.m. Saturday and was under control around 7 p.m., according to Summitville fire chief Dwayne Pinegar.“It was so hot we couldn’t do anything with it so we decided to back off and let it burn for a couple of hours,” said Pinegar. “We were also worried some of that methanol, glycerin and biodiesel might explode.”What began as a flash fire quickly spread.