On the contrary, that there was no death pre-fall is indicated by the fact that death was a result OF the fall.
It is the assertion that there was death pre-fall that is scripturally un-supported
I don't know what text you are talking about, but if there was no death prior to the so called 'fall', then the warning would have no meaning.
For the warning 'that day you will die' to have any impact or meaning, death had to exist, and had to be known.