Police said the day started with some fun for two teenage boys, but ended tragically.
The accident happened on Kalanipuu Street in Hawaii Kai where police said the two friends were having fun down the street.
One boy was holding on to the back of the moped on his skateboard, when he couldn't hold on any longer, he fell off and hit his head on the ground.
The medical examiner said a 16-year-old boy died at the hospital. Investigators believe the moped was going 10-to-15 mph, and they said the teen wasn't wearing a helmet.
"It's dangerous as it is and it's a sad thing that he had a lapse in judgment to do something dangerous like that," said the teenager's friend Jake Edwards.
Friends said the teen loved skateboarding, and could always be found at the Hawaii Kai skate park.
"He always skateboards around here like every since I was little he would always run down on the skateboard," said neighbor Sierra Bassett.
"They always play basketball, ride skateboards, ride bicycles and do things," said neighbor Michael Ohashi.
Those who care about him say they're in shock that something like this could happen as he did a sport many said he was so good at. They said he'll always be known as a nice kid who just loved having fun.
"He's really outgoing, and fun, and good-hearted, humble kid," said Edwards.