September 6, 1901. President William McKinley is shot at the Pan American Exposition in Buffalo, NY. Anarchist Leon Czolgosz is arrested in connection with the attack. September 14, 1901. McKinley dies of complications from his bullet wounds. Vice President Theodore Roosevelt assumes the presidency.
Concrete slab. A concrete slab is a common structural element of modern buildings. Horizontal slabs of steel reinforced concrete, typically between 4 and 20 inches (100 and 500 millimeters) thick, are most often used to construct floors and ceilings, while thinner slabs are also used for exterior paving.
A concrete block is referred to as a concrete masonry unit, or CMU, in the construction industry. Concrete blocks can be solid or hollow, with two or three cores or voids. The blocks also come in a range of standard shapes. Generally, concrete blocks measure 16 inches long by 8 inches wide by 8 inches high, though their actual widths and heights are a quarter-inch less.