"The officer saw him shoot the other person, and he ordered him to drop the gun," said City Police Commissioner Charles H. Ramsey. "He didn't, and [the officer] shot him."
All three were reported in stable condition, Ramsey said.
In his four years involved with the fireworks celebrations in Philadelphia, this was the first shooting nearby, Ramsey said. He noted that it did not occur at the concert in the Art Museum area, but near Love Park, at 16th and JFK Boulevard, where a group of about 1,000 teenagers had gathered earlier in the evening.
"It actually went pretty well," Ramsey said of the annual event, shortly after the fireworks ended, though he added that the large crowd still had to be dispersed.
A four- to five-block area was cordoned off after the shooting and added to the chaos as Occupy demonstrators also continued to move around the area.
Extra police were on duty Wednesday as shifts were extended to 12 hours and anyone who normally would have had the day off was required to work, Ramsey said.
Authorities had no official crowd count for the annual celebration but said they expected 500,000 people to turn out for a concert featuring the Roots, Queen Latifah, Daryl Hall, Common, and Joe Jonas and the fireworks display to follow at around 11. There also was a surprise appearance by Lauryn Hill, a Grammy-winning singer who last week pled guilty in New Jersey to not paying federal taxes.
"There is not an empty space on the Parkway," City Representative Melanie Johnson said earlier in the evening, before the shooting. "Every year, it seems to get bigger and better."
The Roots kicked off the music at 8 with a slow, bluesy, bass-heavy "Star-Spangled Banner." The crowd whistled and waved flags, with hands and hats over their hearts.
The lines were long for frozen treats. And a group of giggling children got relief from the heat at an open fire hydrant at Franklin and 21st Streets.
The celebration got started much earlier in the day with military jets streaking through a hazy blue sky in a flyover above Independence Hall, speeches, and a parade that blended history and pageantry.
"This is the best Fourth of July celebration in the United States of America!" Mayor Nutter promised a sea of spectators already baking on the lawn of Independence Mall during the 10 a.m. opening ceremonies of Wawa Welcome America: Celebration of Freedom.
During the proceedings, 13 men and women from 10 nations took the oath of allegiance to become U.S. citizens, the bells atop Independence Hall tolled 13 times for the original colonies, and actress Ellen Burstyn read excerpts from the Declaration of Independence.
After listing the reasons for breaking free of England and enumerating the inalienable rights the 56 male signers claimed, the Oscar and Tony winner earned extra cheers when she offered a postscript: "I would just like to add that goes for women, too."
Afterward, a two-hour parade snaked through the streets. In addition to including historic regiments, drum-and-bugle corps, and marching bands, the spectacle recalled Sept. 11 and paid tribute to each branch of the military, police, and fire and emergency workers. Bagpipers in tartan kilts and other Highlands regalia played "Amazing Grace" as they marched.
Spectators on both sides of Market Street watched as a tanker fire truck from Shanksville, Pa. - where United Airlines Flight 93 crashed into a field after passengers overpowered hijackers on Sept. 11 - drove slowly down the street.
Some floats and marching groups highlighted contributions that ethnic groups have made to their communities in the United States. Resplendent in their vibrant costumes, dancers from Virginia's Caporales San Simon USA gave parade watchers a glimpse of Bolivia's culture.
Throughout the celebration, demonstrators from what has been billed as the Occupy movement's first National Gathering, who were staked out at Franklin Square, mingled with the thousands who thronged the historic district, at times making their presence known, though causing no disruption.
During the opening ceremonies, several Occupy members in pink and green tops briefly massed on Independence Mall's lawn to spell out "Revolution Now" before many of them found seats in the crowd.
As the official parade snaked through the historic district shortly after 11 a.m., Jim Ulrich, 51, of Appleton, Wis., began to argue with some Occupy members who were walking up Market Street. The electrical engineer told them he did not like the way the movement uses the term "99 percent," he later reported.
"I just don't like that phrase," said Ulrich, who said he was in Philadelphia because his children were competing in an annual chess tournament in Center City.
" 'Ninety-nine percent' demonizes the wealthy people who make up businesses and create jobs. All the people I work for are in the so-called 'one percent,' " he said.
Standing on the sidewalk a few feet away, Nancy Mancias observed Ulrich's conversation.
Mancias, 42, had come all the way from San Francisco to spend the July Fourth week in Philadelphia and to participate in Occupy's five-day event. Dressed in pink clothes bearing Occupy slogans and shielding herself from the sun with a pink parasol, Mancias posed for photos with tourists and holiday spectators.
"We have people here engaged in a heated, passionate discussion about politics in the front yard of Independence Hall," said Mancias, who runs a vocational program in Marin County, Calif.
"I just think that's what we should be doing instead of having barbecues and taking advantage of Fourth of July sales. This is what the country is all about."
Contact Martha Woodall at 215-854-2789 or at firstname.lastname@example.org.