The sound was the first tip and it sent Dereck Grey's father running from the stands.
When Grey's body went limp everyone knew that the Desert Vista senior was in trouble.
Still, his mom stayed in the stands until she received a call from her husband, and then she was no longer just a concerned parent.
"I went into nurse mode," Deanna Grey said. "When I was in the stands I was holding off as a mom because I knew Dereck wouldn't want me running out on the field. Then his dad phoned and said I needed to get down there."
Grey was running out a groundball on Feb. 26 when the throw was to the home plate side of first base. It hit him on the side of the face and a portion of the helmet. It created one of those sounds that instantly turn your stomach because a ball traveling at 80-some mph meeting bone provides a horrific thud.
"That play comes close to happening so many times but never does," Desert Vista baseball coach Stan Luketich. "It was the darndest thing."
Grey was unconscious and when he was brought to he couldn't see anybody and everything was black. Everything eventually came into focus, but he couldn't remember anything after getting hit. It was clear something neurological was happening so he was taken to urgent care and then on to Chandler Regional Medical Center.
"Once we got to the hospital I stopped being nurse and became mom again," said Deanna, who works on the pediatrics floor at Mercy Gilbert Medical Center. "He said something good was going to come from this and all he cared about was when he could play again."
Grey ended up having two fractures in his jaw along with a concussion. He had a 2-and-a-half-hour surgery on March 2 to repair it with a metal plate and his mouth is still wired shut. He hopes to resume baseball drills - even though he was throwing just two days, swollen face and all, after surgery at home - on March 23 if the doctor clears him.
"It is such a shame because he worked harder than ever this offseason," Luketich said. "We hope to get him back and help us the last month of the season."
If Grey has his way, he will do more than just help. The 6-foot-4, 180-pound pitcher/center fielder expects to get back to where he was before the injury.
"I know I can get there," said Grey, with his dad, Rod, helping to interpret. "It's time to get back. We want to finish the season strong and I can be part of it."
Grey, who has received great support from his teammates, lost about 20 pounds at one point. He has put about half of it back on through protein shakes and soup, but he probably won't be able to get in games right away. He will have to work his way back and also wear specially designed helmets when he is pitching or batting.
It is something he will have to get used to but Grey, who is 0-1 with a 3.50 ERA on the season after one start, will do just about anything to get back on the mound.
"I don't think there will be (any hesitation after getting hit)," Grey said. "I just want to play and get back out there."
He had aspirations of signing a scholarship for college, but will most likely have to start at a local junior college. That is something to worry about down the line.
Right now Grey, who says he will never have chocolate milk again because he has had so many protein shakes since surgery, is just as concerned about eating that first real meal once he is able to eat solid foods again.
And that decision has already been made.
"Chipotle! A double-wrapped burrito," Grey said.