NYC school employee, 19, dies after being shot leaving work in Brooklyn; ‘It’s just too much right now’ says his distraught mom(EXCLUSIVE)

A 19-year-old shot in the head as he left his new paraprofessional job in a Brooklyn city school died of his injuries Wednesday as police arrested his alleged killer.

Ethan Holder fought for his life at Brookdale University Hospital after he was shot in broad daylight Tuesday afternoon as he left his job at Public School 203, also known as The Floyd Bennett School, his distraught mother told the Daily News.

“He started in September — he was just starting at this new school,” the woman told The News as she rushed from the family’s Flatlands home to visit her son at Brookdale University Hospital on Wednesday morning.

As she left home, her critically injured son was in critical condition in a Brookldale intensive care unit. “It’s just too much right now,” the distraught mom said.

Holder died of his injuries later on Wednesday — as police announced the arrest of Javier Oates, 19, in the slaying. He was charged with murder, criminal possession of a weapon and criminal use of a firearm, cops said.

Holder left the Flatlands school around 2:50 p.m. Tuesday and headed to a nearby deli at the corner of Avenue M and Utica Ave.

As Holder approached the deli, an approaching car made a U-turn — and then the gunman stepped out of one of its doors and fired off five rounds, police sources said.

Holder was struck in the head and the left thigh in the caught-on-video crime, a police source said. A stray bullet pierced the windshield in a nearby parked car.

Holder, a paraprofessional working with students at the school, managed to stumble into Stars Mini Market before collapsing.

“They shot him outside and he was trying to run inside,” a man who works in the store told The News. “He fell face-up inside our door.”

After the wounded teen ran into the deli, Oates fired at least one shot at the market, said cops.

Oates — who was described as wearing a red hoodie, red sweatpants and a black jacket — then ran to a dark-colored sedan and climbed inside. The car sped off, said police.

“You don’t want to hear of that, especially in proximity of a school,” said Jeff Rosenthal, 68, who works near the school. “Life in the big city. (We) don’t live in Shangra-La. It is what it is.”

A friend of Holder who gave her name as Yeshiva described the victim as a “sweetheart.”

“I don’t know how to feel right now. I don’t want to believe it. ‘Cause we all grew up together as like a family,” said the 21-year-old friend.

Holder was part of Brooklyn’s bustling drill rap scene, and his Instagram page included videos of him drill rapping with friends.

Yeshiva told The News that Holder rapped under the name “Fourteen,” a nod at his young age and appearance.

“He was always the younger one. So they always used to tell him, like, ‘Bro, you look like you’re 14.’”

Yeshiva said Holder enjoyed working as a paraprofessional, a job in which he usually interacted with kids in special education programs.

“He just had that personality,” she said. “The kids wanted to be around him. Parents loved him. He loved it.”

Holder’s mother believes her son was at the wrong place at the wrong time.

“This had to be a random shooting,” she aid. “I don’t believe he has any enemies who would target him.”

In a tweet, Mayor Adams lamented the shooting as a “tragedy.”

“The rivers of violence bringing guns into our communities didn’t begin in our city but they will end here,” he stated. “We will keep our city safe.”

Holder’s mother said the teen had worked at a public school in East New York before his transfer to P.S. 203 at the beginning of the school year.

“He liked it over there,” the mother said of her son’s new job just a mile from home. “Detectives haven’t given me anything yet. We’re just trying to understand what happened.”

Oates, who has one prior sealed arrest in the city, said nothing as he was walked from the NYPD’s 63rd Precinct stationhouse Wednesday evening. He was dressed in a beige sweatsuit, with his right arm in a sling.

What appeared to be two hospital bands were adhered to his wrists, but a police spokesperson said it was unknown if he had been hospitalized.

His arraignment in Brooklyn Criminal Court was pending Wednesday night.