Early reports suggest that the fire spread so fast thanks to newly installed thermal cladding on the exterior. The material is in alarmingly common use across the U.K. and may actually be flammable. Alarm systems in the tower also worked solely on a floor-by-floor basis, while residents had been told previously that if a fire occurred, they should remain in their homes.

This wouldn’t necessarily be bad advice if the building were fully fireproofed and adapted to ensure that fire doesn’t spread from floor to floor. But the fire at Grenfell Tower spread so fast that this advice may have actually left them more vulnerable to harm.

What is far harder to stomach is the official response to constant, well-documented complaints from residents. When protests about KCTMO appeared on the residents’ association blog, the borough had lawyers send letters demanding the post be taken down. As this BBC interview with a resident makes clear, people living in the block were either ignored or threatened by contractors when they raised their concerns.

David Collins of #GrenfellTower residents association gives a shocking account of the local councils refusal to heed residents safety fears. pic.twitter.com/cC47EWBUer — EL4C (@EL4JC) June 14, 2017

Now, the block is uninhabitable and some of those residents have lost their lives.

The spectacular nature of the fire may be a one-off, but the conditions that made it possible are not. A 2011 report found that three quarters of Britain’s social housing blocks were potentially unsafe in a fire. That condition was only exacerbated when many previously publicly owned units were released onto the private market, as part of the Right to Buy scheme. This allowed long-term public housing tenants to buy their apartments at a discount, and many quickly re-sold at a mark-up soon after. As a result, the most desirable projects ended up in part-private ownership. There’s a political dimension to all this that cannot be ignored: In recent years, the state and availability of public housing has been one of the most hotly contested issues in Britain—especially in London.

London’s most acute current issue is a chronic housing shortage. Most of the city is built at fairly low densities, but planning laws and organized resistance by suburbanites have made it very difficult to build enough new housing in the more spacious outer boroughs. Inner-city projects, by contrast, are relatively easy to redevelop because the land is still publicly owned. These areas have become a key target for densification projects, rebuilding, and in-fill construction.

Redeveloping projects like these is especially attractive to cash-strapped boroughs because it helps them manage severe austerity cuts imposed by the central government. By attracting buyers to these properties, the boroughs can generate direct profits and attract wealthier residents who pay higher taxes and use fewer public services. Redeveloping or remodeling public projects also means that boroughs and developers can squeeze out extra revenue by adding homes for the private market, or “affordable” homes that, while cheaper than market rates, still generate some profit.