Explosions at a chemical plant near Houston posed a fresh worry for storm-battered Texas on Thursday while rescuers searched block-by-block for survivors of Hurricane Harvey and the death toll rose to 35 people.

The explosions in Crosby, Texas, were the latest consequence of the historic flooding brought by the most powerful storm to land in Texas in a half-century, which drove tens of thousands from their homes around the U.S. energy hub.

Portions of the state's southeastern coast, including Beaumont and Port Arthur, remained severely flooded, even as some commuters began returning to the streets of parts of Houston. In Beaumont, a hospital was evacuated after losing its water service.