Utica, MI – A grandfather attending his grandchild’s first birthday party was stabbed to death at a park Saturday by a man whom the grandfather had asked to stop doing drugs.

The children and other relatives witnessed the attack, according to the Macomb Daily.

Witnesses said that the attacker had a box of “whippets,” which are containers that have nitrous oxide, on the park bench. The Macomb Daily reported that nitrous oxide use has been known to cause hallucinations.

The grandfather walked over to the bench and asked him to get rid of the drugs because children were at the party and playing at the park.

The suspect was “enraged” according to witnesses and attacked the grandfather. The victim was knocked to the ground and then stabbed more than 12 times, according to one witness who spoke with the Macomb Daily.

"(The victim) fell to the ground, he had blood all over him," said Amanda Pasho, a witness who lives near the park, according to the Macomb Daily. "He had his arms up to fend off the man from stabbing him. The man put his knee in the guy's abdomen to hold him down and then put his arm across his face and began stabbing him with a knife, like non-stop, just jabbing at him with the knife."

"He was enraged, he seemed like he had the strength of the Tasmanian devil," Pasho said, according to the Macomb Daily. "My heart goes out to the family of that poor man. I can't believe this happened in front of them."

The grandfather died at the park.

Witnesses said the knife was eight to 10 inches in length and looked like a machete.

Neighbors heard the grandfather and family members screaming and saw the attack and called 911.

When police arrived, the suspect was still at the park and was arrested at gunpoint by a Shelby Township police officer, according to the Macomb Daily.