What could cause a loss of power steering

Hello, A few things can cause the power steering to fail, and diagnosing the issue is typically not too hard. Does the vehicle leak power steering, or any other fluid? What does the car sound like when you turn the steering wheel? Is the power steering pump belt present? Any strange noises, or any odd feelings through the steering wheel or brake pedal? Does the vehicle make a groaning sound and change engine speed when the steering wheel is turned all the way and forcefully held?