Complex sentence: Volunteer relief workers said that there was such a dearth of resources that even supplies as basic as shovels, cutting tools, and stretchers ran out, and that the rescue process was impeded by large crowds and senseless inattention to organization.
Split into simpler sentences: Volunteer relief workers said that even basic supplies ran out, such as shovels, cutting tools, and stretchers, agreeing that there were not enough resources. Elaborating, they added that the rescue process was impeded by large crowds and senseless attention to organization.