Describe how Escobar’s reign was finally ended.

After the assassination of Luis Carlos Galán, the administration of César Gaviria moved against Escobar and the drug cartels. ... Declaring an end to a series of previous violent acts meant to pressure authorities and public opinion, Escobar surrendered to Colombian authorities in 1991.

Roberto Escobar maintains Pablo fell into the drug business simply because other types of contraband became too dangerous to traffic. As there were no drug cartels then, and only a few drug barons, Pablo saw it as untapped territory he wished to make his own.