Delete all lines from a line with certain string until another line with a diffrent string in a file

file.txt:

start some text works "HELLO" foo test  sum  otherendstart som "other" line with text 'also'  thing  fooend

and I want to delete the line in which "HELLO" is located and then delete all following lines until a line which has end written on it and nothing else!

I know this is a rather weird idea but I'm hoping either some basic bash command could do this or a function to which I pass the first string and the second and it deletes them and all in between!

The file should be looking like this at the end:

start som "other" line with text 'also'  thing  fooend

THANK YOU!