Victor Oquendo has details on the life-threatening heat wave impacting more than 200 millions Americans, and meteorologist Jeff Smith has the heat wave forecast; Perry Russom reports on the deadly boat crash off Miami Beach, where a barge collided with a sailboat from a youth sailing program, throwing overboard all five children and one adult on board, according to officials; Pierre Thomas has the latest on the urgent manhunt underway in Arkansas for a suspect who allegedly killed a couple while they were hiking with their two young daughters in a state park; and more on tonight's broadcast of World News Tonight with David Muir.

Kayna Whitworth reports on the Colorado dentist guilty of murder in the first degree after authorities say he was secretly and systematically poisoning his wife by lacing her protein shakes; Trevor Ault has details on one of the largest recorded earthquakes that struck off Russia's Pacific coast, prompting tsunami waves and panic from Russia to Japan to the U.S., the 8.8 magnitude quake triggered Russia's largest volcano to erupt; Pierre Thomas has the latest on Virginia councilman Lee Vogler attacked and doused with gasoline then set on fire; and more on tonight's broadcast of World News Tonight with David Muir.