Officials evacuate residents of the Chalcots Estate, in London's Camden borough on Friday evening. Camden's local council decided to evacuate the hundreds of households due to safety concerns following the devastating fire that killed 79 people in Grenfell Tower. Alastair Grant/AP hide caption

toggle caption
Alastair Grant/AP

The cladding used in a 2016 refurbishing of Grenfell Tower in London helped last week's fatal fire spread. The combustible material is permitted in some parts of the U.S. Niklas Halle'n /AFP/Getty Images hide caption

toggle caption
Niklas Halle'n /AFP/Getty Images

Tributes to victims of the Grenfell Tower fire are left near the building in West London on Friday. Combustible cladding has been found in a number of similar tower blocks in Britain, Prime Minister Theresa May said. Niklas Halle'n/AFP/Getty Images hide caption

toggle caption
Niklas Halle'n/AFP/Getty Images

A firefighter looks at tributes to presumed victims of the Grenfell Tower fire, after observing a minute's silence at a community center near the apartment building in west London. PA Images via Getty Images hide caption

toggle caption
PA Images via Getty Images