Transcript for Dangerous weather moves across parts of the US
Let's turn to weather and storms across the country. Dangerous thunderstorms in the northeast. Fierce lightning strikes in Harrisburg. You see them there. To the west, monsoon rains triggering flash flooding in the Vegas strip. Here is rob Marciano. Reporter: Mother nature dealing a bad hand to the Las Vegas strip. Torrential rain turning roadways into rivers, unloading onto this casino parking lot. Six people rescued. This taxi driver waiting for help on the roof of his car. Now he's getting his passengers out. Reporter: As the water rises, he pulls his passenger up though a window. Cars also swamped in New Orleans, flash flooding happening in the crescent city tonight. Lightning tearing through the night sky in Pennsylvania. And wrecking havoc near Salt Lake City. Sending medical. Two teenagers that were struck by lightning at Lilly lake. Reporter: Three sisters struck during a family camping trip. The father told the three young girls to go over into some trees and try and avoid the lightening. Reporter: Something you should not do in a thunderstorm. Tonight, two of the girls in critical condition after being airlifted to the hospital. Their father reviving them with cpr. The northeast drying out from flash flooding there. Airports still rebounding after more than 1,300 cancelled flights. A lot happening now over the big easy. Let's get to rob with the forecast. Rainfall rates. You can see the crescent city. The thunderstorm just sitting there. Wet weather there. And apart Kansas, Missouri and another batch of rain coming tonight. Another four inches so flooding is potential. And the complex system to the south and more thunderstorms over the next 48 hours in Oklahoma, Arkansas and the Tennessee valley as well. Rob, thanks so much.
This transcript has been automatically generated and may not be 100% accurate.