A US Airways flight attendant on a layover in Mexico City was found dead in his hotel room early Saturday as an investigation begins and fellow crew members were temporarily relocated.

An investigation is underway in the death of Nick Aaronson, who was based in Phoenix, Arizona, a flight attendants union said.

In a release, the Association of Flight Attendants Council 66 said preliminary findings do not indicate a safety breach at the hotel.

“Therefore we do not believe our crew members are at risk,” the AFA said. The union said layover crews would be temporarily relocated to an alternative occasion.

Authorities are investigating the circumstances of Aaronson’s death, a spokeswoman, for the Tempe,Arizona-based US Airways told the Arizona Republic.