"These will be matters for the scientists and the engineers ... to find out exactly how the fire started, why it spread so quickly and what could have been done to prevent it," Fitzpatrick told Sky News.

A local community organization, the Grenfell Action Group, had warned about fire dangers at the building since 2013. In a series of blog posts, the group raised concerns about testing and maintenance of fire-fighting equipment and blocked emergency access to the site.

"All our warnings fell on deaf ears, and we predicted that a catastrophe like this was inevitable and just a matter of time," the group said in a blog post Wednesday.

KCTMO said it is cooperating with investigators and that it was aware of tenant complaints. "We always take all concerns seriously and these will form part of our forthcoming investigations," it said in a statement.

The Kensington and Chelsea Council promised a full investigation into Wednesday's tragedy and a public accounting. The UK government also ordered checks at tower blocks that have had or are going through similar renovations as those at Grenfell Tower.

AP