Original sentence: Trench rescue is a specialized form of rescue, a subset of confined space rescue
Edited sentence: Dirt is placed behind the plywood sheets to fill cavities from the collapse and to support the plywood and maintain pressure against the bracers.However, it is given the least amount of respect by rescue personnel due to ignorance of the power and weight of the collapsing dirt walls.In a special situation, many different types of material found at the job site might be used by the rescuer to prevent further engulfment of the victim.In fact, many of the tools are simple, such as wedges made of wood, sheets of plywood, and shovels.Once the ditch is secured, the rescue team may enter the ditch and recover the trapped victim.Plywood sheets are placed along the sides of the trench, and shoring bracers are placed between the sheets.Pneumatic, hydraulic, and mechanical shoring are designed specifically for trench rescue and are available to professional rescue personnel.Power tools should never be used, as these may cause injury to a trapped victim.Searching for the victim and excavation around the victim should only be performed with your hands.The area around a collapse should not be approached by any unnecessary personnel as this might cause further collapse of the sides.This is to prevent further collapse of the ditch sides.Trench rescue doesn't use many high tech tools.Trench rescue is a highly specialized form of rescue, a subset of confined space rescue.Trench rescue training should only be practiced in a controlled professional environment designed specifically for trench rescue training