Keywords: Trench safety - backhoe lowering trench box into trench (9247884221).jpg A trench box is lowered into a trench by a backhoe https //www flickr com/photos/niosh/9247884221/ Trench safety - backhoe lowering trench box into trench 2010-03-17 17 35 https //www flickr com/people/25069384 N03 National Institute for Occupational Safety and Health NIOSH from USA PD-USGov NIOSH http //flickr com/photos/25069384 N03/9247884221 2015-04-23 18 51 25 United States Government Work Construction Safety Shoring Work Workplace National Institute for Occupational Safety and Health |