Heat wave impacting millions across U.S., Iran releases dramatic video of seized British oil tanker, and original recorded footage of the moon landing found.Watch NBC Nightly News With Lester Holt at 6:30 p.m. ET 5:30 p.m. CT (or check your local listings). 1:58 Deadly Heat Wave: 154 Million At Risk2:57 Heat Wave Damaging Infrastructure And Power Grids4:11 Heat Wave's Dangerous Impact On Your Health7:30 New Video Iran Claims Is British Tanker Seizure8:07 British Call Tanker Seizure A Hostile Act9:26 Vatican Mystery: Are Bones Of Missing Girl?11:16 Couple Murdered On Canadian Road Trip13:10 Rare Look Inside Chinese Tech Giant14:31 U.S. Believes Huawei Is A National Threat