(CBS News) CHICAGO – Violent crime in America has fallen for six straight years, with homicides last year down nearly 6 percent. But in Chicago, there have been 275 homicides this year, most of them gang related. The nation’s third-largest city had 17 shootings this past weekend alone.

Mayor Rahm Emanuel on Monday announced a new attack on gangs, including a plan to board up or tear down the abandoned buildings they use to run their operations. But the violence continues to take it’s toll, as CBS News learned from the front lines in a major hospital.

At the Cook County Trauma Center in Chicago’s Stroger Hospital, one ambulance after another delivers victims of the gang violence that just won’t stop.

The unit treats about 1,500 gunshots and stabbings a year.

“I heard like four or five (gunshots),” one patient tells a nurse.

In the first six months of this year, Chicago had 22 percent more murders that New York — a city with 5.5 million more people.

Medics attend to a man on a gurney: “One stab wound, approximately one inch in length. … He has lost about 20 CCs of blood.”

In the midst of the mayhem is Dr. Fred Starr, who was in charge of the unit the weekend we visited.

“I’ve seen more people probably this year who have been caught in the crossfire, or you know, caught a stray bullet and that certainly is alarming,” Starr said. He said he’s angry at the violence adding, “When I see the children — I have two children of my own, and it certainly makes it very personal for me.”

The victims include 7-year old Heaven Sutton, shot to death selling candy outside her house; and 10-year old Kitanna Peterson, shot as she played in the spray from a fire hydrant. She was treated at the trauma center last week.

“They just happen to be in the wrong place at the wrong time,” Starr said. “They’re collateral damage to some of the violence that is happening out on the streets.”

Starr shrugs off the notion of feeling overwhelmed.

“It gets very busy here but we actually get used to it,” he said.

We met paramedic Wesley Metcalf moments after he brought in a man with a head wound.

“It’s busy all over the city. Everybody’s out doing stuff,” he said. “We had a call last month, young man going to his prom. Four o’clock in the afternoon with five people shot. We picked him up. He still had on his tuxedo, shot in the chest. Brung him here. He was [dead on arrival].”.

“Seventeen years old,” Metcalf said. “Going to his prom.”

Among veteran gang members treated at Stroger there’s a nonchalance that’s almost breathtaking.