As kindergartners headed out the door to be picked up by parents, a fight broke out in the parking lot. Heated words. Raised voices. Let's settle this down the street, someone was heard saying. We'll settle this like men.
They were men: Parents, not students.
And now police are trying to figure why the confrontation on a scorching summer morning ended the way it did: with Carmello D'Alessandro run down in the street and left to die, and 31-year-old Anthony Michael Parrinello facing a second-degree-murder charge.
The conflict began, police say, in the parking lot of Canyon Springs School in Anthem, just before 11 a.m. Monday as kindergarten let out.
Witnesses told police that Parrinello called out 42-year-old D'Alessandro, challenging him to a fight at a nearby Walmart.
Both men had children enrolled in the K-8 school, officials confirmed.
Parrinello headed to the store, police believe, but D'Alessandro walked the other way.
Police say Parrinello, not finding his opponent at the store, hunted him in his blue Ford Excursion.
A passer-by found D'Alessandro run down by a vehicle, lying in a wide street about two blocks from the school. He later died in a nearby hospital of the wounds.
Police found Parrinello at a nearby park, where they said he worked. The Excursion had been wiped off, Phoenix Sgt. Trent Crump said. Soon came a search warrant, and court records show a search of his vehicle found blood and other evidence.
City parks officials confirmed the man had worked for them at one time but would not discuss the matter.
Parrinello admitted having a verbal argument, but denied killing D'Alessandro, police said.
But police say Parrinello ran him down and kept driving. They recommended second-degree-murder charges against him.
What they and the school can't say about the death is why.
"The reasons for the fight remain unclear," Crump said.
Investigators interviewed witnesses in the parking lot but said no one saw the hit-and-run.
Parrinello was held on $1 million bond.
Both men have had brushes with the court system.
Parrinello was accused of punching his girlfriend in the back in 2007, but the case was dropped. An ex-wife got a protective order against him, court records show.
D'Alessandro had a protective order filed against him, too. An unnamed woman wanted the court to stop him from harassing her. An ex-wife said she was seeking child support.
Parrinello has one child at Canyon Springs, while D'Alessandro had one child and three stepchildren there, Deer Valley Unified School District spokeswoman Heidi Vega said.
Tuesday, the school brought in a team of counselors to help kids and others make sense of events, she said. Late Tuesday afternoon, the principal sent out a letter to parents explaining what happened.
"Canyon Springs is a family, a community that loves and supports one another," Principal Tricia Graham wrote. She did not provide details of the case, which she said police continue to investigate.
Down the street, neighbors were concerned, too. One saw the crime-scene tape Monday afternoon and asked if a child had been hurt.
Christopher Williams of 12 News and Cassondra Strande of The Arizona Republic-12 News Breaking News Team contributed to this story.