Wildfire smoke from Canada captivated the East Coast this week, but data shows that much of the United States has been dealing with smoke since early May.

Police arrested a 15-year-old student after he allegedly brought an AR-15 and ammunition to a Phoenix high school on Friday, authorities said.

Calls for a ban on AR-15 semiautomatic rifles escalate after every mass shooting, but many Americans still want to be able to buy the military-grade weapon.

Heavy snow in 2023 primed California for floods. NBC News is tracking river levels as the snow melts.

The state’s high peaks stored historic amounts of snowfall this winter. Now the state’s aging water management systems could be at risk.

New air quality data shows that 8 out of every 10 of the larger cities in the U.S. experienced improvements in average PM2.5 values from 2021 to 2022.

How the FDIC is able to guarantee money for Silicon Valley Bank and Signature Bank account holders, and how it limits bank failure contagion effects.

Data reviewed by NBC News showed that from 2018 to 2022, Norfolk Southern averaged slightly more accidents per million miles than the other six Class-I railroads.

Breaking down the numbers behind the Russia-Ukraine war, on the anniversary of Vladimir Putin's full-scale invasion.

More than 100 earthquakes have occurred in Turkey and Syria since Feb. 3.

Bed Bath & Beyond said it plans to close another 150 stores as it continues to reorganize its finances.