User blog comment:Endor 66/Why do Ruby and Yang have different last names/@comment-24342832-20140303053656/@comment-4010415-20140303190512

Another reason for saying Summer died is the gravestone in the Red Trailer and the intro sequence. In the Red Trailer, we get a closeup that shows what's written on it:

"Summer Rose

Thus Kindly I Scatter"

Plus, in Red Like Roses, it says "Red like roses fills my dreams and brings me to the place you rest." Place you rest = Your grave.

In the intro, Ruby is kneeling in front of the gravestone, with a white-cloaked person standing on the other side of it. That person's legs stop being visible at a certain point, giving them a ghostly appearance.