Law Enforcement Officers are seen at the scene of an explosion on West 23rd Street September, 18, 2016 in New York. An explosion rocked one of the most fashionable neighborhoods of New York on September 17 night, injuring 29 people, one seriously, a week after America's financial capital marked the 15th anniversary of the 9/11 attacks. Mayor Bill de Blasio indicated the blast was not accidental, even if there was no known link to terrorism. The blast occurred in Chelsea -- an area packed with bars, restaurants and luxury apartment blocks -- at a typically bustling time of the weekend / AFP PHOTO / KENA BETANCURKENA BETANCUR/AFP/Getty Images

Law Enforcement Officers are seen at the scene of an explosion on West 23rd Street September, 18, 2016 in New York. An explosion rocked one of the most fashionable neighborhoods of New York on September 17 night, injuring 29 people, one seriously, a week after America's financial capital marked the 15th anniversary of the 9/11 attacks. Mayor Bill de Blasio indicated the blast was not accidental, even if there was no known link to terrorism. The blast occurred in Chelsea -- an area packed with bars, restaurants and luxury apartment blocks -- at a typically bustling time of the weekend / AFP PHOTO / KENA BETANCURKENA BETANCUR/AFP/Getty Images

Law Enforcement Officers are seen at the scene of an explosion on West 23rd Street September, 18, 2016 in New York. An explosion rocked one of the most fashionable neighborhoods of New York on September 17 night, injuring 29 people, one seriously, a week after America's financial capital marked the 15th anniversary of the 9/11 attacks. Mayor Bill de Blasio indicated the blast was not accidental, even if there was no known link to terrorism. The blast occurred in Chelsea -- an area packed with bars, restaurants and luxury apartment blocks -- at a typically bustling time of the weekend / AFP PHOTO / KENA BETANCURKENA BETANCUR/AFP/Getty Images

SPD party leader and German Vice Chancellor, Economy and Energy Minister and Sigmar Gabriel (L) and Berlin's mayor Michael Mueller, top candidate of the social democratic SPD party shake hands during the electoral evening in Berlin after a regional election on September 18, 2016 in Berlin. Some 2.5 million eligible voters in Berlin will choose both a new city-state parliament and 12 local district assemblies. / AFP PHOTO / Odd ANDERSENODD ANDERSEN/AFP/Getty Images

SPD party leader and German Vice Chancellor, Economy and Energy Minister and Sigmar Gabriel (L) and Berlin's mayor Michael Mueller, top candidate of the social democratic SPD party react during the electoral evening in Berlin after a regional election on September 18, 2016 in Berlin. Some 2.5 million eligible voters in Berlin will choose both a new city-state parliament and 12 local district assemblies. / AFP PHOTO / Odd ANDERSENODD ANDERSEN/AFP/Getty Images

SPD party leader and German Vice Chancellor, Economy and Energy Minister and Sigmar Gabriel (L) and Berlin's mayor Michael Mueller, top candidate of the social democratic SPD party shake hands during the electoral evening in Berlin after a regional election on September 18, 2016 in Berlin. Some 2.5 million eligible voters in Berlin will choose both a new city-state parliament and 12 local district assemblies. / AFP PHOTO / Odd ANDERSENODD ANDERSEN/AFP/Getty Images

SPD party leader and German Vice Chancellor, Economy and Energy Minister and Sigmar Gabriel (L) and Berlin's mayor Michael Mueller, top candidate of the social democratic SPD party react during the electoral evening in Berlin after a regional election on September 18, 2016 in Berlin. Some 2.5 million eligible voters in Berlin will choose both a new city-state parliament and 12 local district assemblies. / AFP PHOTO / Odd ANDERSENODD ANDERSEN/AFP/Getty Images

SPD party leader and German Vice Chancellor, Economy and Energy Minister and Sigmar Gabriel (L) and Berlin's mayor Michael Mueller, top candidate of the social democratic SPD party react during the electoral evening in Berlin after a regional election on September 18, 2016 in Berlin. Some 2.5 million eligible voters in Berlin will choose both a new city-state parliament and 12 local district assemblies. / AFP PHOTO / Odd ANDERSENODD ANDERSEN/AFP/Getty Images