I'm sick of candlelight vigils.

Sick of writing about dead young people.

Sick of antiviolence marches that don't make a difference.

You probably are, too. The constant onslaught of shootings takes a collective toll on our psyche. We become desensitized.

But then there are cases like that of Sandrea Williams that stay with you. When I heard about her slaying over the weekend,  I was struck by the tragedy of it all — a mother losing a child right before Mother's Day. Police say Sandrea had just visited with her mother and was standing around with a group of about a half-dozen teens near Simpson and Carlton Streets in West Philly when she was struck down Friday evening.

She was only 17.

It's so upsetting. Sandrea shouldn't be dead. She should be alive and safely ensconced inside her tight-knit family from Jamaica, looking forward to another of her family's epic Sunday dinners of oxtails, rice and beans, curried mutton, jerk chicken, and other traditional dishes.

A high school junior at Camelot Academy in North Philly, Sandrea was on the brink of adulthood and excited about finally having her own car – a silver 2009 Nissan Sentra recently purchased for her by her aunt. She only had it for a week.

It's not right that she's dead. Sandrea should be cruising the city in her car. She should be helping her aunt get to her doctor's appointments. She should be stopping at the home of an elderly neighbor to put drops in his eyes and take him to the grocery store, as she often did. She should be cutting her uncle's lawn to earn extra cash to buy new sneakers.

"The night when she was murdered, she was actually here hustling to buy her grandmom, me, and her mom Mother's Day gifts," said Naisha Rhoden, Sandrea's aunt. "But her main reason for coming over really [was] because a friend was going on a prom and she wanted to see the kid go off to the prom. When the kids got to the prom and heard that she got shot, they all left and went to the hospital in their prom ball gowns and suits."

Sandrea had just left her mother's front steps in the 300 block of North Simpson on Friday when 23 bullets rang out shortly before 10:30 p.m.,  one of them mortally wounding her. Two of her friends, also teens, were each shot in a leg. Philadelphia Police Homicide Capt. John Ryan said the scene was "almost like a terror attack." Police have made no arrests.

"They took someone who was really loved from us," said Nadia Syblis, Sandrea's mother, who had been sitting on her front steps but ran inside when shots rang out. She returned only to discover that her daughter had been struck.

Sandrea's memorial service is set for June 1, to allow relatives from outside the country time to travel to Philadelphia.

Meanwhile, the monsters who committed this horrible crime roam free. Someone knows who the two gunmen are, and that person needs to do the right thing and turn them in. Please call the Citizens' Crime Commission at 215-546-TIPS or homicide detectives at 215-686-3334 if you have any information about the case. There's a $20,000 reward for information leading to an arrest and conviction

"It saddens me that no one will come forward and give this mother some level of closure with regard to her daughter being killed," said Darin Toliver of the Black Men at Penn School of Social Work, who has been posting on social media about the case.  "It's indicative of the signs of the time and how the code of not snitching has really festered in our society."

And that's another thing that sickens me.