WEWOKA, Okla. (AP) -- The state fire marshal was investigating on Thursday the cause of a fire at a chemical plant here that sent flames and large plumes of black smoke into the sky, forced evacuation of nearby residents and the closing of a state highway.
The blaze destroyed two buildings at Cochran Chemical Co., which provides chemicals for oil drilling companies, and caused an estimated $500,000 in damage, said Wewoka Fire Chief Kevin Anderson.
The fire started between 1:30 p.m. and 2 p.m. Wednesday when a spark ignited chemicals that were being mixed by employees, Anderson said.
The spark may have resulted from static electricity, but officials do not know for sure.
``The state fire marshal is doing interviews with employees of the business,'' Anderson said Thursday. ``We turned it over to him and should have a report in three days.''
The fire was out by Thursday morning and residents were free to return home after monitors during the night found the air to be normal, Anderson said.
Oklahoma 56 that runs near the plant was shut down for 16 1/2 hours before being reopened at 7 a.m. Thursday.