Fish shredded in power head!!!!!! Help

Hi TRT I fed my trachyphyllia a price of krill and so I turned off my powerhead. Next morning, I turn on the power head and fling! This fish come flying out of the power head and purple scales ft acting down to the sand bed. Oh no!! I got so worries and saw him swim into the rock breathing terribly fast. I felt terrible. The power head is small, 400 GPH I feel like a terrible fish keeper