Depends on what you mean by "collapse." You can use faint, subside, breakdown, crumple, etc.
Ohayou Gozaimasu (Good Morning)
If you're speaking to a friend or in a similar casual situation, you would use the word ohayou (おはよう).
Do you have any option choices? If not I would think it's the harp. (:
Its mostly for laminate flooring and its water proof and other stuff