It's definitely not a dead language – a new Fortran front-end has recently been accepted into the LLVM project, joining Clang. So LLVM's only in-tree supported languages (excluding the various IRs) will be C, C++, Objective-C, and Fortran. It had been scheduled for merge into the LLVM monorepo 2 days ago, but has been delayed pending some additional architecture review.
Latin was dead long before it stopped being used in written works. It died when it stopped being spoken and stopped changing. I don't know if Fortran would be considered dead by the "no longer adapting" definition, but that it's still in use isn't proof it's alive.
Latin never died or stopped changing or stopped being spoken; it is still spoken by about a billion people today — they just stopped calling it “Latin” at some point.