Grenfell Tower insulation and cladding in fire test
Footage from BBC Panorama shows what happens when the insulation and the cladding that covered Grenfell Tower is exposed to a flame.
The cladding core melts and lights the insulation, the video shows. Panorama says that before the disaster, these two products were never tested together.
Panorama has said the insulation had never passed the required safety test and should never have been on the building. The manufacturer of the insulation, Celotex, said it is co-operating with the police investigation and inquiry.