A man in Alabama who killed two people will be the first person in the US to die by a new gas. His name is Kenneth Eugene Smith and he has been waiting to die for 35 years. He tried to stop his death but the courts said no.
The new gas is called nitrogen and it makes people stop breathing. Some people say it is very painful and wrong. Alabama says it is better than the old way of killing people with drugs. Alabama will not say how it will use the gas. Smith will die on Thursday night.