Suisun City, Calif. -- Solano County firefighters battled a three-alarm blaze Friday at a massive fertilizer manufacturing plant in a remote area outside of Fairfield. The grass and structure fire began just after 5 a.m. in an unincorporated part of Suisun City, about 45 miles northeast of San Francisco and a few miles from Travis Air Force Base, according to the county fire department. Late Friday morning, investigators still did not know what caused the fire at EB Stone & Son, Inc. or whether the burning materials were toxic, said Suisun City Fire Chief Mike O'Brien. "Our biggest concern is...