Johnson finally sent in federal troops with tanks and machine guns. Detroit continued to burn for three more days until finally, 43 were dead, 2,250 were injured, 4,000 were arrested; property damage ranged into the hundreds of millions. The biggest wave of riots came in April 1968, in over a hundred cities after the assassination of Martin Luther King. Johnson called for even more billions to be spent in the cities and another federal civil rights law regarding housing, but this request had little Congressional support. Johnson's popularity plummeted as a massive white political backlash took shape, reinforcing the sense Johnson had lost control of the streets of major cities as well as his party.[184] Johnson created the Kerner Commission to study the problem of urban riots, headed by Illinois Governor Otto Kerner.[57] According to press secretary George Christian, Johnson was unsurprised by the riots, saying: "What did you expect? I don't know why we're so surprised. When you put your foot on a man's neck and hold him down for three hundred years, and then you let him up, what's he going to do? He's going to knock your block off.