First, police were called after a 3-year-old was found wandering alone in a diaper this afternoon on West Gage Avenue near South Woods Avenue.
Then, when officers went looking for the parents, they say they found a drug lab inside a home.
They arrested three men and placed the child in protective custody.
A search warrant was obtained for the home.
Several nearby houses also had to be evacuated as hazardous materials experts assessed the situation.