Looks like Tecoma stans, aka yellow bells or esperanza. This is a full sun plant, so that may be part of the problem. It is also just as likely as not that the flowers (some but not necessarily all) are aging and so look wilted and then drop. That is the normal course of events for any flowering plant - the flowers won't last forever :-))

Agree with gardengal.

Here are mine last year: in full sun, one blooming, one before next round of blooms. Normal behavior for these beauties. I can only have them as annuals here (North central Tx).