War in Ukraine live updates: Chernobyl nuclear site loses power after days of Russian combat

Emergency generators are providing power to critical safety systems at the Chernobyl nuclear site, Ukraine's government said, but repair to the transmission lines is impossible because Russian fighting. Also, Ukrainians are trying to evacuate via what are supposed to be safe corridors, including one from the besieged port city of Mariupol, but witnesses say shelling continues.

Here's what we're following today:

Harris to Poland: The vice president travels to Eastern Europe one day after the Pentagon rejected Poland's offer to share its fighter jets with Ukraine.

Chernobyl site under stress: Ukraine's nuclear agency said the site lost power, and generators only have enough fuel for 48 hours.

Risky evacuations: Despite the assurances that the fighting would be suspended in Mariupol, witnesses told NPR that Russian forces are blocking people from leaving.