Texas mission, scene of Mexican siege and massacre in 1836 (5)
I believe the answer is:
alamo
(Other definitions for alamo that I've seen before include "The answer is a place of siege" , "Site of 1836 massacre in Texas" , "Where Davy Crockett died, 1836" , "ill-fated mission" , "Where Davy Crockett met his end" .)