A 23-year-old man, trying to climb into the bed of a moving pickup truck, suffered critical injuries when he fell off the truck Sunday evening.

Maui police said the man climbed out of the cab of a Toyota Tacoma truck through the rear sliding window into the bed of the truck at about 7:45 p.m. on the Kula Highway about 1.7 miles south of Kealakapu Road.

The man then fell out of the truck bed while the truck was moving.

The truck was driven by another 23-year-old man.

Police said the passenger suffered life-threatening injuries and was taken to Maui Memorial Medical Center for treatment.