The storm was several miles out to sea and white cumulous clouds dotted a blue sky, according to Jim Handschuch, who was a lifeguard on the beach and administered CPR.
Burns on the body showed that lightning hit McCarthy's head and left through his left hip and he couldn't be revived, according to the Newark Star-Ledger.
"It was a crisp, beautiful day and there was something mysterious about the clouds," said Handschuch, who is now 49 and principal at Lacey Township Middle School. "They were tall and really different."
"I recall sitting on the lifeguard stand and I saw two lightning bolts come from way off past the horizon," he told ABCNews.com. "There was a glow and within seconds I heard, 'Someone has been hit by lightning.'"
As for the friend, he was "knocked out or startled" by the bolt and taken to the hospital, according to Handschuch. "He was kind of in shock, knowing his friend had been hit. That is a trauma unto itself."
After the incident, when Handschuch was forced to close the beach, sunbathers argued with him.
Now, he said, "I always respect lightning."