When Charlie Kirk crumpled to the ground from a gunshot wound, his team rushed to grab him and rush him to a hospital in an SUV ... and a mentor who was there is recalling that harrowing scene.

Christian radio host Frank Turek got emotional Sunday at the Kirk memorial, telling the crowd what it was like on the ride to the hospital.

Frank says Charlie was so tall, they had one door propped open as they raced to the hospital ... describing how Charlie's body was being held by his team in the back seat.

He says he was looking down at Charlie and screaming, and Charlie was looking up. Frank says Charlie was looking through him and into "eternity."

Frank says he's been told Charlie felt no pain and died instantly.

He says Charlie's team did everything they could to save him ... but it sounds like there was nothing anyone could have done to keep him alive.