Answer:
1. Because they have better opportunities in the USA. In terms of money, stable jobs, a way out of poverty.
2. Latin America countries have a high rate of crime, you can get killed there sooner or later if you happen to walk the wrong way.
3. As humans, we want to live in security, people from Latin America have to live constantly in fear.
4. In short, people migrate usually because they want their lives to be better. If their lives weren't in danger or suffering from poverty, then they would have no reason to leave their countries. Sometimes, they are left with no choice but to migrate to save themselves from threats that would compromise their lives and well-being, as well as leaving because of lack of opportunities, money, education, etc...