Politicians smiled. Construction companies made millions. And grateful tenants moved into a home at last. With pre-cast slabs and easy on-site assembly, Britain's housing shortage had a solution: system building. Today, less than 20 years later, many of those tenants are screaming to get out, and many of those buildings are coming down: unsafe, unfit, unsound. It is a tale of bad design, inept supervision, appalling workmanship, and a whole lot of people who didn't know (or care) what was going on. David Jones investigates a disaster whose scale is only just becoming apparent. And for which we will be paying - in cash and social consequences - well into the next century.