The week in photos, Sept. 16-23

This week, a plane crashes in a Reno air show, high drama unfolds at the United Nations and the death penalty takes center stage in Jackson, Ga.

Sen. Susan Collins, R-Maine, holds up a postcard she received from an anonymous Army soldier in Afghanistan thanking her for her support of the repeal of "Don't Ask, Don't Tell," Tuesday, Sept 20, 2011, on Capitol Hill in Washington. After years of debate and months of final preparations, the U.S. military passed a historic milestone Tuesday with the repeal of a ban on gays serving openly in uniform. Photo: AP Photo/Charles Dharapak

The repeal of 'Don't Ask, Don't Tell' 

Sen. Susan Collins, R-Maine, holds up a postcard she received from an anonymous Army soldier in Afghanistan thanking her for her support of the repeal of "Don't Ask, Don't Tell," Tuesday, Sept 20, 2011, on Capitol Hill in Washington. After years of debate and months of final preparations, the U.S. military passed a historic milestone Tuesday with the repeal of a ban on gays serving openly in uniform. Photo: AP Photo/Charles Dharapak

Freed American Shane Bauer, center, is welcomed upon his arrival in Muscat, Oman. After more than two years in Iranian custody, two Americans convicted as spies took their first steps toward home on Wednesday, Sept. 21, 2011. Photo: AP Photo/Sultan Al-Hasani

American hikers freed from Iranian prison 

Freed American Shane Bauer, center, is welcomed upon his arrival in Muscat, Oman. After more than two years in Iranian custody, two Americans convicted as spies took their first steps toward home on Wednesday, Sept. 21, 2011. Photo: AP Photo/Sultan Al-Hasani

A P-51 Mustang airplane crashed during an air show in Reno, Nevada on Friday, Sept. 16, 2011. The vintage World War II-era fighter plane piloted by Jimmy Leeward plunged into the grandstands during the popular annual air show. Ten people were killed in the accident. Photo: AP Photo/Garret Woodman

Plane crashes into crowd at Reno airshow 

A P-51 Mustang airplane crashed during an air show in Reno, Nevada on Friday, Sept. 16, 2011. The vintage World War II-era fighter plane piloted by Jimmy Leeward plunged into the grandstands during the popular annual air show. Ten people were killed in the accident. Photo: AP Photo/Garret Woodman

IMF Managing Director Christine Lagarde speaks at the IMF-World Bank Annual Meeting in Washington, D.C. on Friday, Sept. 23, 2011. Photo: AP Photo/Jose Luis Magana

The IMF-World Bank Annual Meeting 

IMF Managing Director Christine Lagarde speaks at the IMF-World Bank Annual Meeting in Washington, D.C. on Friday, Sept. 23, 2011. Photo: AP Photo/Jose Luis Magana

Police in riot gear wait and watch a group of anti-death penalty protesters for death-row inmate Troy Davis in Jackson, Ga., Wednesday, Sept. 21, 2011. Davis was executed later that night for the killing of off-duty Savannah officer Mark MacPhail. Photo: AP Photo/Stephen Morton

The execution of Troy Davis 

Police in riot gear wait and watch a group of anti-death penalty protesters for death-row inmate Troy Davis in Jackson, Ga., Wednesday, Sept. 21, 2011. Davis was executed later that night for the killing of off-duty Savannah officer Mark MacPhail. Photo: AP Photo/Stephen Morton

A man walks past a screen showing Hong Kong's benchmark Hang Seng stock index diving 4.9 percent to 17,911.95 at a brokerage firm in Hong Kong on Thursday, Sept. 22, 2011. World stocks skidded lower Thursday, stung by the U.S. Federal Reserve's pessimistic assessment of the global economy and the perceived ineffectiveness of measures to kickstart growth. Photo: AP Photo/Kin Cheung

World financial markets continue to gyrate 

A man walks past a screen showing Hong Kong's benchmark Hang Seng stock index diving 4.9 percent to 17,911.95 at a brokerage firm in Hong Kong on Thursday, Sept. 22, 2011. World stocks skidded lower Thursday, stung by the U.S. Federal Reserve's pessimistic assessment of the global economy and the perceived ineffectiveness of measures to kickstart growth. Photo: AP Photo/Kin Cheung

The New York City Metropolitan Transportation Authority completed tunneling for the first phase of the Second Avenue Subway on Thursday, Sept. 22, when a tunnel-boring machine (TBM) reached the Lexington Avenue-63rd Street station, breaking into the existing tunnel. The completion of tunneling marks a major milestone in the $4.45 billion project that will provide service from 96th Street to 63rd Street as an extension of the Q train. Photo: AP Photo/Mary Altaffer

Breaking through underground 

The New York City Metropolitan Transportation Authority completed tunneling for the first phase of the Second Avenue Subway on Thursday, Sept. 22, when a tunnel-boring machine (TBM) reached the Lexington Avenue-63rd Street station, breaking into the existing tunnel. The completion of tunneling marks a major milestone in the $4.45 billion project that will provide service from 96th Street to 63rd Street as an extension of the Q train. Photo: AP Photo/Mary Altaffer

The airplane transporting Pope Benedict XVI is shown approaching land in Erfurt, Germany, on Friday, Sept. 23, 2011. Pope Benedict XVI is on a four-day official visit to his native Germany. Photo: AP Photo/Frank Augstein

The Pope visits Germany 

The airplane transporting Pope Benedict XVI is shown approaching land in Erfurt, Germany, on Friday, Sept. 23, 2011. Pope Benedict XVI is on a four-day official visit to his native Germany. Photo: AP Photo/Frank Augstein

U.S. delegates walked out during Iranian President Mahmoud Ahmadinejad's speech during the 66th session of the United Nations General Assembly at U.N. headquarters on Thursday, Sept. 22, 2011. Photo: AP Photo/Andrew Burton

UN General Assembly 

U.S. delegates walked out during Iranian President Mahmoud Ahmadinejad's speech during the 66th session of the United Nations General Assembly at U.N. headquarters on Thursday, Sept. 22, 2011. Photo: AP Photo/Andrew Burton

Julie Bank, right, executive director of New York's Animal Care and Control, reintroduces Willow, a 6-year-old calico cat, to her owners Chris Squires and his children Jack, 10, and Lauren, 3. Willow disappeared from her Colorado home five years ago and was found this week on the streets of New York City, 1,600 miles away. Photo: AP Photo/Mary Altaffer

The cross country cat 

Julie Bank, right, executive director of New York's Animal Care and Control, reintroduces Willow, a 6-year-old calico cat, to her owners Chris Squires and his children Jack, 10, and Lauren, 3. Willow disappeared from her Colorado home five years ago and was found this week on the streets of New York City, 1,600 miles away. Photo: AP Photo/Mary Altaffer