CROSBY, Texas (AP) — Explosions and fires rocked a flood-crippled chemical plant near Houston early Thursday, sending up a plume of acrid, eye-irritating smoke and adding a new hazard to Hurricane Harvey’s aftermath. The plant’s owners warned more explosions could follow because a loss of refrigeration was causing chemicals stored there to degrade and burn. The Environmental Protection Agency and local officials said an analysis of the air for toxic materials found no reason for alarm.