Why are my beets not fermenting?

My first attempt (RAW BEETS) - large mason jars, 2 tbsp sea salt, water up to 1" below lid. After a week I opened the lid to "burp" the gas out, but there was nothing, no fizz, just dead beets in room temperature water. I got sketched out and threw them out.

2nd try (COOKED BEETS)- I tried using 2 tbsp whey which I rendered from yogurt plus a tbsp of sea salt, after 3 days, same thing, no gas or fizz just warm salty dead beets.

My house is always at 70 degrees.

I am very disappointed. I have had great success with carrots in the past.

any insight would be appreciated.