Which of the Following Disasters Are Considered NA-TECH (Natural-Technological) Disasters

Which of the following disasters are considered NA-TECH (natural-technological) disasters? (Select all that apply.)

A) Constant rain led to mud slides, and whole neighborhoods were buried.
B) An earthquake caused structural collapse of bridges and highways in the area.
C) People stampeded out of the overcrowded arena, trampling people who had fallen.
D) River flooding resulted in overflow of the sewage plant and contaminated drinking water throughout the city.
E) The tsunami washed out all the power and telephone lines throughout the downtown area of the city.
F) Volcanic eruption covered the town with ash, making it difficult to breathe.