Complex sentence: Starting in the 1970s, the students of Texas A&M at Galveston created their own Aggie Bonfire, mirroring the traditions of the College Station student body, but ceased observance of the tradition after the structure in College Station collapsed in 1999, killing twelve students.
Split into simpler sentences: Starting in the 1970s, the students of Texas A&M at Galveston created their own Aggie Bonfire, mirroring the traditions of the College Station student body. However, the Galveston campus ceased observance of the tradition after the structure in College Station collapsed in 1999, killing twelve students.