Clark issued a statement about his son, Brandon, and Brandon's friend Scott Morin Monday morning. The two were hit with a shotgun blast, he said.
"Scott has pulled through his surgeries and is in stable condition," he said. His son has now had two surgeries, but luckily there is no damage to his spinal chord.
"His spleen, kidney, and upper and lower colon have been severely damaged," Clark wrote. "He remains in serious but stable condition. We were advised last night that he will need at least one more surgery scheduled for tomorrow to try and repair the organs that were blown to bits."
According to police, a man showed up with a shotgun during a gathering at a Queenston Road apartment at about 2 a.m. Sunday and opened fire.
Clark and Morin were rushed to hospital with bullet wounds, while another man and a woman were injured jumping off the third-floor balcony to escape.
The gunman was also shot and was pronounced dead at the scene, police say.
Police did not say if someone had returned fire or if the gunman's fatal wound was self-inflicted. They are not, however, seeking any suspects.
Clark called the incident a "random act of violence."
"These four friends are wonderful, hard-working citizens, who were just at the wrong place at the wrong time. Please pray for our son, Brandon and all of the victims," he said.
"We've been told that the deceased assailant was a mentally ill young man. Please pray for his family as they struggle with this personal tragedy."