Can juice become alcohol without yeast?

I left a bottle of juice in my room a week or two ago when I was tripping and I found it today. It was the frozen canned juice concentrate you mix with water so I’m thinking it could be more sugary than normal juice, but it didn’t have any yeast. It smells like it could be alcoholic and when I opened the bottle it released air like home fermented alcohol. I was wondering if it’s possible it became alcohol and if it would be safe to drink if there is a chance of that having happened.