Heat Dome and Storms Rock July 4

Extreme weather upended July 4 celebrations across the eastern United States as a punishing heat dome baked the region and severe thunderstorms swept through.

In Washington, D.C., the National Mall was evacuated due to lightning threats, delaying President Trump's speech and stranding thousands of attendees when entrances were later blocked.

Temperatures topped 100 degrees Fahrenheit in several cities, contributing to at least 19 suspected heat-related deaths in New Jersey.

More than 185 million people were under heat or storm advisories, straining power grids and transit systems.