Grenfell tower was a tragedy which occurred as a consequence of actions taken and failing to be taken by those who owned the building and organised its refurbishment, and who disregarded the repeated attempts of residents to raise objections about safety issues. It appears clear that the fact that these residents were overwhelmingly poor was a major factor in why they were treated in this way, and why they were there in the first place (people with severe mobility problems placed in flats on the 20th storey, for example.)

No, it wasn't "class war". That term is never used for actions in which poorer or marginalised people are treated badly. It is only used when they fight back.