Gas in air box

Hey forum. So recently I had discovered that there was water in my ranchers gas tank. Today I decided to drain everyone out do fill it with fresh fluid and all that. So upon opening the air box I notice a liquid in there and turns out it was gas. I did not know until now that my brother had turned the tab up vertically to wash the bottom of the tab couple days ago. After that I tried cranking it and didn’t turn on. How did the gas get in the air box? How can I fix it. Is it considered to be flooded?