This undated family photo provided by Damon Stewart shows 15-year-old Hadiya Pendleton of Chicago.
CHICAGO - A 15-year-old girl with a big smile and big plans has become the face of this city's climbing homicide numbers.
Hadiya Pendleton, who performed at President Obama's inauguration with her high school's band and drill team Jan. 21, was shot in the back Tuesday afternoon as she and other King College Prep students took shelter from a driving rain under a canopy in Vivian Gordon Harsh Park on the city's South Side.
Police said an unidentified gunman jumped a fence, ran toward the group and opened fire, then jumped into a car and left the scene. Pendleton was hit in the back. A male victim, 16, is in serious condition.
The park is about 1 mile from Obama's Chicago home.
Community groups are offering an $11,000 reward for information leading to Pendleton's killer.
Chicago Police Superintendent Garry McCarthy said at a news conference Wednesday that the gunman might have believed she and her friends were members of a rival gang. Pendleton had no arrest record and there's no indication she was in a gang, police said.
Obama spokesman Jay Carney called the death a "terrible tragedy." Chicago Mayor Rahm Emanuel, a Democrat who is pressing for tougher gun laws, urged anyone with information about the shooting to come forward.
"She had dreams," he said of Pendleton, "and this gang-banger, this punk, took that away."
Chicago has had 42 homicides so far this year, the most at this point since 2002, police spokeswoman Melissa Stratton said. The city had 506 murders in 2012, up from 435 the previous year.
Nathaniel Pendleton, the victim's father, asked at the news conference why it's dangerous for the city's youth to hang out at parks in the afternoon. Such tragedies, he said, aren't "only happening in bad neighborhoods. It's happening in good neighborhoods. It's happening in the suburbs."
He said the shooting "took the light of my life."
Michael Pfleger, pastor of Chicago's St. Sabina Catholic Church, said the nation "should be just as outraged" by Pendleton's death as it was by the Dec. 14 school massacre in Newtown, Conn.
Hadiya, a sophomore who was planning to attend college, was "a great, great, wonderful young lady - a walking angel," said her adult cousin, Shatira Wilks. She played sports and was a majorette, cheerleader and Honor Roll student, she said.
Wilks said she hopes her cousin's death will help spur changes in the community.
"If people play a role in raising their children correctly," she said, "this kind of thing won't happen."