Question: The event that caused the destruction of America's "Black Wall Street" in 1921 resulted in how many deaths according the American Red Cross?

Context paragraphs:
List of earthquakes in 1948: This is a list of earthquakes in 1948.  Only magnitude 6.0 or greater earthquakes appear on the list.  Lower magnitude events are included if they have caused death, injury or damage.  Events which occurred in remote areas will be excluded from the list as they wouldn't have generated significant media interest.  All dates are listed according to UTC time.  This would go down as one of the deadliest years of the 20th century.  The main factor behind this was the earthquake which struck Turkmenistan that left 110,000 people dead in early October.  This was the deadliest single earthquake since 1923 when a great quake struck Tokyo.  Other events during the year caused many deaths including one in Japan in June which resulted in over 5,000 deaths.  The number of magnitude 7.0+ events (18) was around normal with the biggest event being in the Philippines measuring 7.8.  Clusters of large events were reported in Latin America and the southwest Pacific particularly Fiji in the early part of the year.

Tulsa race riot: The Tulsa race riot, or Tulsa race riot of 1921, occurred between May 31 and June 1, 1921, when a white mob started attacking residents and businesses of the African-American community of Greenwood in Tulsa, Oklahoma, in what is considered one of the worst incidents of racial violence in the history of the United States.  The attack, carried out on the ground and by air, destroyed more than 35 blocks of the district, at the time the wealthiest black community in the nation.  More than 800 people were admitted to hospitals and more than 6,000 black residents were arrested and detained, many for several days.  The Oklahoma Bureau of Vital Statistics officially recorded 39 dead, but the American Red Cross estimated 300, a number supported by historians since then.

American Red Cross Motor Corps: American Red Cross Motor Corps (also known as American Red Cross motor service) was founded in 1917 by the American Red Cross (ARC).  The service was composed of women and it was developed to render supplementary aid to the US Army and Navy in transporting troops and supplies during World War I, and to assist other ARC workers in conducting their various relief activities.  The diverse character of the work included canteen work, military hospitals, camps and cantonments, home service workers, outside aid, office detail, other ARC activities, and miscellaneous services, such as the 1918 flu pandemic.

American Red Cross National Headquarters: The American Red Cross National Headquarters is a located at 430 17th Street NW in Washington, D.C. Built between 1915 and 1917, it serves both as a memorial to women who served in the American Civil War and as the headquarters building for the American Red Cross.  It was declared a National Historic Landmark in 1965.

American Red Cross Nursing Service: The American Red Cross Nursing Service was organized in 1909 by Jane Arminda Delano (1862-1919).  A nurse and member of the American Red Cross, Delano organized the nursing service as the reserve of the Army Nurse Corps to be ready just before the entry of the United States into World War I.  Key wartime decisions were made by Delano along with Mary Adelaide Nutting, president of the American Federation of Nurses, and Annie Warburton Goodrich, dean of the Army School of Nursing.

American Red Cross Volunteer Life Saving Corps: The American Red Cross Volunteer Life Saving Corps (ARCVLSC) is a non-profit organization made up of volunteer lifeguards.  It is a division of the American Red Cross, which provides volunteer lifeguards to Jacksonville beaches and internationally through Lifeguards Without Borders.

List of earthquakes in 1946: This is a list of earthquakes in 1946.  Only magnitude 6.0 or greater earthquakes appear on the list.  Lower magnitude events are included if they have caused death, injury or damage.  Events which occurred in remote areas will be excluded from the list as they wouldn't have generated significant media interest.  All dates are listed according to UTC time.  Several great shocks affected the planet in 1946.  The largest was one of the most significant in human terms.  The quake itself was a magnitude 8.6 striking on April 1 in Alaska resulting in a tsunami mainly affecting Hawaii.  The consequence of this apart from many deaths was the foundation of the Pacific Tsunami Warning Center.  This organisation has helped to substantially reduce the death toll of tsunamis in the Pacific, although there have been a few exceptions, including the 2011 Japan event.  Japan itself was heavily affected in 1946 by a large quake hitting in December, causing 1,362 deaths.  The Dominican Republic was another nation that suffered great destruction in August.  Turkey, Peru, and Turkmenistan all saw earthquakes causing many deaths.  In general, 1946 was a busy year, with 21 events measuring above 7.0 and three exceeding a magnitude of 8.0.

Jarrett Barrios: Jarrett Tomás Barrios (born October 16, 1968) is the chief executive officer of the American Red Cross Los Angeles Region, a former politician and activist.  Prior to this, he served at the CEO of the American Red Cross of Massachusetts.  Barrios served as a member of both the Massachusetts House of Representatives and the Massachusetts Senate and became the first Latino and first openly gay man elected to the Massachusetts Senate.  He subsequently served as president of the Blue Cross and Blue Shield of Massachusetts Foundation and, later, of the Gay & Lesbian Alliance Against Defamation (GLAAD).

National Shelter System: The American Red Cross and the Federal Emergency Management Agency (FEMA) together developed the National Shelter System (NSS).  Under the National Response Plan now called the National Response Framework auspices, American Red Cross, is the Co-Primary Agency with FEMA responsible for the Mass Care portion of Emergency Support Function #6 - Mass Care, Temporary Housing and Human Services.

Greenwood, Tulsa: Greenwood is a neighborhood in Tulsa, Oklahoma.  As one of the most prominent concentrations of African-American businesses in the United States during the early 20th century, it was popularly known as America's "Black Wall Street" until the Tulsa race riot of 1921, in which the Oklahoma state government with the assistance of Tulsa's white residents massacred hundreds of black residents and razed the neighborhood within hours.  The riot was one of the most devastating massacres in the history of U.S. race relations, destroying the once thriving Greenwood community.

Supporting paragraphs: Greenwood, Tulsa Tulsa race riot
Answer: 300