How Could God Kill All the Firstborn Babies in the Tenth Plague?

Questions about how God could kill all the firstborn babies in the tenth plague, how to respond to someone who says God committed genocide when he destroyed the earth during the flood, and whether God still creates calamity today as it says in Isaiah 45:7.

How could God kill all the firstborn babies in the tenth plague?


How should I respond to someone who says God committed genocide when he destroyed the earth during the flood?


Does God still create calamity today as it says in Isaiah 45:7?