The Superdome caught on fire Tuesday morning ... with thick smoke and flames billowing out of the famed New Orleans arena's roof.
It's unclear what caused the issues at the Saints' stadium ... authorities so far have only told us "the fire is not burning anymore."
We're working to get further details.
As we previously reported, the Saints have relocated out of New Orleans in the wake of Hurricane Ida -- moving their Week 1 game against the Packers from the Superdome to Jacksonville.
The team -- which beat Green Bay in the opener but lost to the Panthers in Carolina on Sunday -- is not currently scheduled to play in the N.