A lonely ribbon of discarded crime scene tape and a bullet-riddled white sedan occupied the middle of Kershaw Street near 52nd Street on Sunday night, attracting curious onlookers who hadn’t been around earlier in the day, when the West Philadelphia block filled with the unmistakable sound of gunfire.

Some neighbors sat on their front porches, sharing the details they’d heard, and wondered whether there was reason to worry about retaliatory violence that could endanger a nearby day-care center.

According to police, three men, ages 28, 21, and 28, were shot just before 2:30 p.m., and admitted to Penn Presbyterian Medical Center in critical condition.

As with so many shootings in Philadelphia, the other crucial details — who did this, and why? — remained a mystery Sunday night.

But during what proved to be a particularly bloody weekend, Kershaw Street wasn’t the only place where residents were left to whisper at crime scenes and lament the city’s endless gun violence epidemic. Eleven people were shot, two of whom died.

The latest incident occurred about 9:30 p.m. when gunfire erupted on the 2200 block on North 23rd Street in North Philadelphia and a 23 year old man who was talking to a friend was shot in the back, police said. The victim and the friend ran and they drove to Temple University Hospital, where the wounded man was reported in stable conditiojn.

About the same time, a 24-year-old man was shot in both of his legs and his lower back on Lindley Avenue near Sixth Street in Olney, police said. He was admitted to Einstein Medical Center in critical condition.

About 40 minutes earlier, a 30-year-old man was shot twice at 44th and Brown Streets in West Powelton. He was admitted to Penn Presbyterian in critical condition.

Shortly after 5:30 p.m., a 42-year-old man was shot multiple times at 67th and Dorel Streets in Southwest Philadelphia, according to police. He was taken to Penn Presbyterian, where he was pronounced dead at 6:31 p.m. Investigators had no suspects.

At 3:55 p.m., a 38-year-old man was shot in the back on Arthur Street near Crispin Street in Holmesburg, and admitted to Jefferson Torresdale Hospital in stable condition. Police determined that he’d been shot with a pellet gun, but no arrests had been made.

Minutes earlier, a 23-year-old man was shot in the neck and a 21-year-old man was shot in the shoulder when they attempted to buy drugs from two other men behind a Santucci’s Square Pizza on Cottman Avenue near Frankford Avenue in Northeast Philadelphia, police said.

The victim who’d been shot in the neck was air-lifted to Temple University Hospital in critical condition, while the other man was listed in serious but stable condition at Temple. No arrests had been made.

On Saturday night, a 46-year-old man was shot and killed in Upper Roxborough, and a 44-year-old man was shot and critically wounded in Mill Creek in a separate incident.

Last year, about 1,400 people were shot in Philadelphia; the city’s Department of Public Health has estimated that gun violence survivors can face an average of $46,632 in medical costs. More than 500 people have been shot in the city so far this year.

Police Commissioner Richard Ross recently said that nearly 90 percent of the city’s 138 murders this year have been committed by people using guns. He announced plans to put dozens of more officers on the streets this summer by adjusting their assignments and schedules.