JUDY WOODRUFF:

But first: the nation's opioid crisis.

Overdose deaths are on the rise across the country, in 2015, surpassing gun homicides for the first time. One of the hardest-hit states is Maryland, where the governor today declared a state of emergency to fight the epidemic.

But, for more than a year, the city of Baltimore has been training everyday citizens in how to use a lifesaving antidote, an approach that's catching on across the country.

NewsHour producer Pamela Kirkland visited Baltimore to find out more.