Question

When disaster struck something was wrong with the aircraft he kept a cool head. Which is the best way to revise the sentence using dashes?When disaster struck—something was wrong with the aircraft—he kept a cool head.
When disaster—struck—something was wrong with the aircraft—he kept a cool head.
When disaster struck—something was wrong with the aircraft, he kept a cool head.
When disaster struck, something was wrong with the aircraft—he kept a cool head.

Answer 1

When disaster struck, something was wrong with the aircraft—he kept a cool head.

I believe this is the correct way.

Answer 2

When disaster struck, something was wrong with the aircraft-he kept a cool head.