Shocking new video has emerged showing the moment a medivac plane nosedived and exploded in a ball of flames in Pennsylvania, killing all 6 people on board.

The dramatic footage was shot on a dashcam affixed to a car stopped at a red light in Philadelphia Friday night.

Check it out ... the medivac jet transporting a young patient and her mother with 4 crew members aboard plummets from the night sky and hits the ground, turning into a fireball before everyone's eyes in the near distance. One stunned motorist jumps out of their car to get a better look at all the destruction.

Previous footage published by TMZ captured the fiery plane crash, but from further away.

Meanwhile, the Federal Aviation Administration says the child and her mom were heading back to Mexico after the girl received treatment at a Philly hospital. The Learjet was planning to make a pit stop at Springfield-Branson National Airport in Missouri before traveling to Tijuana, Mexico.

Investigators are now trying to determine what caused the plane to go down.