What happend to the second garden of the disbeliever?

In Surat al-Kahf we find the story with the example of the two men quoted in the verses 32 to 44 . While at first in the verses (18:32-33 ) the speech is about two gardens, later on only a single garden seems to be addressed. Does this mean that only one garden of the disbeliever has collapsed or how should I understand the story?