Help, I prepared an 11" hexagon cake this morning and it fell.  Not sure what happened.  Oven right on, baked for 40 min's checked and baked another 5 minutes.  Any suggestions.

ADid the tester come out clean? Two guesses based on the very limited info provided would be that the cake was under-baked or overleavened, either due to the wide pan or overbeating the eggs. Have you baked a cake this size before?

Hi.  No this is the first time.  I was nervous.  So kept checking on it.  after 40 minutes I kept opening and checking it and each time another 5 minutes.  The next two came out fine.