STILLWATER, Oklahoma - Heartbreak in Stillwater Sunday night as the community mourns the loss of one of their own.

Police say a former OSU student was shot in the head at a party early Sunday morning. The toughest part for people to grasp in the tragedy is that police say the person, who pulled the trigger was holding the gun thinking it was a toy.

"I was really shocked, like I thought it was a joke. Then I found out it was real and how it really happened, and I was sad, and feel very bad for his family and friends," said former classmate Madison Malcolm.

A promising life cut short, and many are puzzled that the always smiling, kindhearted friend they know as Alex Vierling is no longer with them.

"I always knew that he had a lot of friends and he was always happy. He was always trying to make people's days. I saw him in the hallway always laughing, joking around. He was a really nice kid."

Malcolm grew up with Vierling at Stillwater High School and knew him as an avid baseball player, always in the gym and always with big dreams. She's stunned that just next door to the gas station where she works is the very place where Vierling's dreams would come to an end.

It was just after midnight Sunday at a big end-of-the-semester party in the 500 block of South West Street where Stillwater Police responded to the shooting. Officers say one person at the party was handling a pistol like a plaything and shot Vierling in the head.

"It's crazy, just people messing around. You don't think that that big of a tragedy could happen, especially for that young of a kid," Malcolm said.

Vierling was rushed to Stillwater Medical Center and then to OU Medical Center where he was pronounced dead, just days before Christmas at 21 years of age.

Stillwater Police have questioned several students at the party, but no arrests have been made.

Anyone with information about the shooting is asked to call the Stillwater Police Department (405) 372-4171.