老猫, please help: do we have a case in the US

My father had COPD, and had to be on oxygen 24/7 by doctor's presciption. Earlier this year, he wanted to go back to China. Because we trust US airlines more, we arranged him to fly with a US airline. However, his hometown does not have direct flights from the US, so for the domestic leg in China, we had to use a China airline. We applied the in-flight oxygen servive and supplied doctor's statement. The application was approved by the airline. However, when he boarded the plane in China, the oxygen generator was clearing not working. Because he can not fly without oxygen, he had to be sent to a local hospital to stay on oxygen, where he was surrounded by patients who were getting IVs for 36 hours. He passed away 10 days later. After the fact, the airline denied any wrong doings. We have been adived by the local attorneys not to pursue a law suite up against such a big company in China.

My main question is whether we have a case in the US, where justice is better served. We applied the oxygen service through the US branch of the airline. The oxygen device they provided is made by a US company.