The smaller the coffin, the more monstrous the murder.

And along with the kid-size casket at the funeral on Wednesday for 5-year-old Laylah Petersen, there will be a harrowing statistic:

Eleven children under the age of 13 have been shot in the city of Milwaukee so far this year.

And little Laylah had not even been out in the street.

She had been in the presumed safety of her home, sitting on her grandfather’s lap and watching television on Thursday evening, when a dozen shots were fired at the house. A random slug that seems to have been intended for nobody in particular tore through a wall and struck the child in the head.

“We believe that this bullet read ‘to whom it may concern,’” Capt. Aaron Raap, head of the investigations division of the Milwaukee Police, later said. “And that concerns all of us.”

The same day as that shooting, Raap had sent out a memo praising his cops for their role in the successful prosecution of a young man for the killing of 10-year-old Sierra Guyton, who had been struck in the head by a stray round in a school playground in May.

Sierra had clung to life for seven weeks before finally succumbing to her wound. The child’s mother, LaTayna Anderson, offered a prayer for other parents.

“I just pray that everyone just keep their children safe,” Anderson said. “I would not bear this on no one.”

The mother also made a plea to the violent ones who wreak such havoc.

“I just ask: Can you all please put down the guns? Just put the guns down.”

A week after Sierra’s funeral, a man who had just completed a prison sentence for attempting to shoot a cop got into a gunfight with somebody while driving a van occupied by seven children. A 10-year-old boy and an 11-year-old girl were wounded.

“We have remorseless, reckless criminals in possession of high-quality firearms shooting at each other, and they don’t care who they hit,” Milwaukee Police Chief Edward Flynn said.

The police noted that they had recovered in excess of 1,000 firearms so far this year, nearly as many as New York, which has more than 12 times the population. Milwaukee’s murder rate is four times that of New York.

But that was still one-fourth the murder rate of the country’s most dangerous city, New Orleans. And Laylah’s family never imagined that she was in the slightest danger as she sat happily on her grandfather’s lap at 6 p.m. on Thursday.

In the stunned aftermath, her grieving relatives spoke of her as “our wild child,” incandescently alive, irrepressibly cheerful and delightfully quirky. One aunt said Laylah loved “sparkles, glitter, anything girly,” adding, “Any time you watch the movie Frozen, her favorite song was ‘Let It Go’ and she would sing it all the time.” Another aunt recalled something Laylah had said to her when they went trick-or-treating on Halloween just a few days before.

“I love you more than science!”

And thanks to science, the family found some consolation in donating Laylah’s heart to give another child a chance at life. The police chief, Flynn, announced that he was going to keep Laylah’s picture in his uniform shirt pocket next to his own heart.

“She’s going to be in our hearts, like her little baby heart is going to be in somebody else’s,” Flynn told reporters Saturday. “She will always be remembered, not just by her family, but by that family that she has given her little heart to.”

Laylah and her older sister, Destiny, attended the school affiliated with Our Lady of Good Hope Roman Catholic Church. A teacher there put a teddy bear on Destiny’s empty desk, and those who so desired left notes of condolence.

The pastor, Father Mike Barrett, recalled seeing Laylah at the weekly Wednesday morning service, where the children are given a chance to offer a prayer of their own composing. Barrett had chanced to place a paternal hand on her head as he passed the microphone to the student next to her.

“Excited, willing, open to learning,” Barrett later said of Laylah. “She always had a smile on her face. She was a joy to be around.”

The very next day, Laylah’s head was pierced by that “to whom it may concern” bullet. This week’s prayer service was Tuesday, with a picture of Laylah set up at the front. Barrett arrived wondering what he could possibly say.

The children then proceeded to say it all for him, taking turns with the microphone as they would at the regular weekly prayer service, but now speaking of their grief over the loss of their friend. They eulogized Laylah as only children could.

“Sand castle builder… tag player,” Barrett recalled.

The funeral was set for Wednesday, exactly a week after that moment when Barrett last saw her. He figured on letting the gospel, specifically Matthew 1:28, guide his homily.

“Come unto me, all ye that labor and are heavy laden, and I will give you rest.”

At the conclusion of the funeral Mass, the kid-size coffin from the monstrous murder was then to be taken from the church to Holy Cross Cemetery. And there, the sand castle builder and tag player who loved her aunt more than science would be buried.

Guns.