Airport workers and their relatives in Brussels, Belgium, hold a candlelight vigil Wednesday, March 23, to pay tribute to those who were killed in <a href="index.php?page=&url=http%3A%2F%2Fwww.cnn.com%2F2016%2F03%2F22%2Fworld%2Fgallery%2Fbelgium-airport-explosion%2Findex.html" target="_blank">terrorist attacks </a>the day before. On Tuesday, explosions rocked the city's airport and a subway station.
Airport workers and their relatives in Brussels, Belgium, hold a candlelight vigil Wednesday, March 23, to pay tribute to those who were killed in terrorist attacks the day before. On Tuesday, explosions rocked the city's airport and a subway station.
PHILIPPE HUGUEN/AFP/Getty Images
Belgian national flags are projected onto the National Gallery in London's Trafalgar Square on March 23.
Belgian national flags are projected onto the National Gallery in London's Trafalgar Square on March 23.
Matt Dunham/AP
A woman in Brussels pauses after people observed a minute of silence at the Place de la Bourse on March 23.
A woman in Brussels pauses after people observed a minute of silence at the Place de la Bourse on March 23.
Christopher Furlong/Getty Images
Teresa Mancheno, a maintenance worker at Newark Liberty International Airport, attends a vigil in Newark, New Jersey, on March 23.
Teresa Mancheno, a maintenance worker at Newark Liberty International Airport, attends a vigil in Newark, New Jersey, on March 23.
Julio Cortez/AP
European Union flags fly at half-staff outside the European Commission in Brussels on March 23.
European Union flags fly at half-staff outside the European Commission in Brussels on March 23.
PATRIK STOLLARZ/AFP/Getty Images
A young girl lights a candle at the Place de la Bourse in Brussels on Tuesday, March 22.
A young girl lights a candle at the Place de la Bourse in Brussels on Tuesday, March 22.
Carl Court/Getty Images
An image of the Belgian flag is displayed on the Trevi Fountain in Rome on March 22.
An image of the Belgian flag is displayed on the Trevi Fountain in Rome on March 22.
GABRIEL BOUYS/AFP/Getty Images
The Eiffel Tower is lit up with the colors of the Belgian flag on March 22.
The Eiffel Tower is lit up with the colors of the Belgian flag on March 22.
Marc Piasecki/Getty Images
Servicemen with Azov, a Ukrainian volunteer battalion, hold torches during a tribute ceremony at the Belgian Embassy in Kiev, Ukraine, on March 22.
Servicemen with Azov, a Ukrainian volunteer battalion, hold torches during a tribute ceremony at the Belgian Embassy in Kiev, Ukraine, on March 22.
ANATOLII STEPANOV/AFP/Getty Images
U.S. President Barack Obama and his family observe a moment of silence as they attend a baseball game in Havana, Cuba, with Cuban President Raul Castro, right, on March 22.
U.S. President Barack Obama and his family observe a moment of silence as they attend a baseball game in Havana, Cuba, with Cuban President Raul Castro, right, on March 22.
Ismael Francisco/Cubadebate via AP
A woman reads messages written on the ground at Brussels' Place de la Bourse on March 22.
A woman reads messages written on the ground at Brussels' Place de la Bourse on March 22.
KENZO TRIBOUILLARD/AFP/Getty Images
A New York City church holds Mass for victims of the Brussels attacks on March 22.
A New York City church holds Mass for victims of the Brussels attacks on March 22.
Spencer Platt/Getty Images
A man places flowers outside the Belgian Embassy in Moscow on March 22.
A man places flowers outside the Belgian Embassy in Moscow on March 22.
KIRILL KUDRYAVTSEV/AFP/Getty Images
A man looks at flowers and messages outside the stock exchange in Brussels on March 22.
A man looks at flowers and messages outside the stock exchange in Brussels on March 22.
Geert Vanden Wijngaert/AP
Democratic presidential candidate Hillary Clinton, center, stands for a moment of silence during a roundtable with tribal leaders in Puyallup, Washington, on March 22.
Democratic presidential candidate Hillary Clinton, center, stands for a moment of silence during a roundtable with tribal leaders in Puyallup, Washington, on March 22.
Carolyn Kaster/AP
A woman leaves a bouquet of flowers at the base of the Belgium and European Union flags, which were flying at half-staff March 22 at the Belgian Embassy in Washington.
A woman leaves a bouquet of flowers at the base of the Belgium and European Union flags, which were flying at half-staff March 22 at the Belgian Embassy in Washington.
Al Drago/CQ Roll Call/getty images
Activists in Multan, Pakistan, condemn the Brussels attack on March 22.
Activists in Multan, Pakistan, condemn the Brussels attack on March 22.
Asim Tanveer/AP
A woman lays flowers at the steps of the Belgian Embassy in Berlin on March 22.
A woman lays flowers at the steps of the Belgian Embassy in Berlin on March 22.
Sean Gallup/Getty Images
A boy at a makeshift migrant camp shows support for the victims near the village of Idomeni, Greece, on March 22.
A boy at a makeshift migrant camp shows support for the victims near the village of Idomeni, Greece, on March 22.
ANDREJ ISAKOVIC/AFP/Getty Images
Mayors of Istanbul districts walk with consuls from various countries, including Belgium, during a protest condemning terrorism on March 22.
Mayors of Istanbul districts walk with consuls from various countries, including Belgium, during a protest condemning terrorism on March 22.
Islam Yakut/Anadolu Agency/Getty Images
People in Turin, Italy, take part in a rally to remember the victims on March 22.
People in Turin, Italy, take part in a rally to remember the victims on March 22.
MARCO BERTORELLO/AFP/Getty Images
France's Parliament observes a minute of silence on March 22.
France's Parliament observes a minute of silence on March 22.
ERIC FEFERBERG/AFP/Getty Images
Members of Quebec's National Assembly have a moment of silence on March 22.
Members of Quebec's National Assembly have a moment of silence on March 22.
Jacques Boissinot/The Canadian Press via AP