In 1950, the city was 23.8% black. By 1970, it was 46.4% black. After Martin Luther King, Jr. was murdered in Memphis, Tennessee on April 4, 1968, the Baltimore riot of 1968 started. It lasted until April 12, 1968. The riot cost the city about $10 million (US$ million in 2021). During the riot, 11,000 Maryland National Guard soldiers and US Army soldiers tried to protect the city. It is possible to see some effects of the riots today. Parts of North Avenue, Howard Street, Gay Street, and Pennsylvania Avenue are barren, empty, and not taken care of.