Emergency services attend to a large explosion at a warehouse in Bristol, England, Thursday Dec. 3, 2020. A local British emergency services department says there have been multiple casualties following a large explosion at a warehouse near the southwest England city of Bristol. (Ben Birchall/PA via AP)LONDON – Four people died following an explosion in a silo that holds treated biosolids at a wastewater treatment plant near the southwest England city of Bristol, police said Thursday. A fifth person was injured during the explosion at the plant in the industrial area of Avonmouth, but the injuries are not considered life-threatening, Runacres said. “Deeply saddened to learn that four people have lost their lives in the water works explosion in Avonmouth,” Johnson said on Twitter.