Original sentence: However, after the two main employers, Pertusola Sud and Montedison, collapsed by  the late 1980s, Crotone was in economic crisis, with many residents losing their jobs and leaving to find work elsewhere.The Cathedral, originally from the 9th-11th century, but largely rebuilt
Edited sentence: By the late 1980s Crotone was in economic crisis, with many residents losing their jobs and leaving to find work elsewhere.Unfortunately, the two main employers, Pertusola Sud and Montedison, collapsed.the Cathedral, originally from the 9th-11th century, but largely rebuilt