The US Supreme Court says it will not stop Alabama's nitrogen gas execution planned for Thursday night. It will be the nation's first execution using nitrogen gas. Convicted murderer Kenneth Smith survived a botched lethal injection in 2022 that helped prompt a review of the state's death penalty procedures. The justices denied Smith's request to stay his execution and declined to hear his legal challenge that Thursday's execution violates Eighth Amendment protections against cruel and unusual punishment. Smith said the first failed attempt caused him severe trauma. More local videos here: https://youtube.com/@9news Subscribe to NEXT: https://youtube.com/@Nexton9NEWS Stay connected: 9NEWS Website: https://www.9news.com/ Facebook: https://www.facebook.com/ilike9news Twitter: https://twitter.com/9NEWS Instagram: https://www.instagram.com/9newsdenver/ Download the 9NEWS App: https://www.9news.com/appredirect/ Sign up for the 9NEWSLETTER: https://www.9news.com/email 9NEWS (KUSA) is located in Denver, Colorado.