Six people have been taken to hospitals after a gas explosion started a major fire in a San Francisco Bay Area suburb. The explosion damaged several homes and sent heavy smoke into the air. Local outlets report possible injuries from the Hayward explosion. A spokesperson for Pacific Gas & Electric Co. said a construction crew damaged an underground gas line around 7:35 a.m. Thursday. The company clarified that it was not their workers. The utility says it isolated the damaged line and stopped the gas flow at 9:25 a.m. The explosion occurred shortly afterward.