Complex sentence: The building's first cupola was damaged by a hurricane in the early 1800s, the second deteriorated before the Great Earthquake of 1886, and the third was not placed until 1981 when the building opened as a museum.
Split into simpler sentences: The building's first cupola was damaged by a hurricane in the early 1800s. The second deteriorated before the great earthquake of 1886, and the third was not placed until 1981 when the building opened as a museum.