Members of the NYPD, FBI, ATF and other agencies invesitgate the the scene, following a late night 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 / Bryan R. SmithBRYAN R. SMITH/AFP/Getty Images

Members of the NYPD, FBI, ATF and other agencies invesitgate the the scene, following a late night 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 / Bryan R. SmithBRYAN R. SMITH/AFP/Getty Images

Members of the NYPD, FBI, ATF and other agencies invesitgate the the scene, following a late night 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 / Bryan R. SmithBRYAN R. SMITH/AFP/Getty Images

(From L) French junior minister for Digital Economy Axelle Lemaire, French junior minister for Trade, Handicraft and Social and Solidarity Economy Martine Pinville, French junior minister for Budget Christian Eckert, French Finance Minister Michel Sapin and French Secretary of State for Industry, Christophe Sirugue walk on September 18, 2016 during the National and Cultural Heritage Days (Journees du Patrimoine) at the French ministry of Economony and Finance in Paris. / AFP PHOTO / JACQUES DEMARTHONJACQUES DEMARTHON/AFP/Getty Images

(From L) French junior minister for Digital Economy Axelle Lemaire, French junior minister for Trade, Handicraft and Social and Solidarity Economy Martine Pinville, French junior minister for Budget Christian Eckert, French Finance Minister Michel Sapin and French Secretary of State for Industry, Christophe Sirugue talk together on September 18, 2016 during the National and Cultural Heritage Days (Journees du Patrimoine) at the French ministry of Economony and Finance in Paris. / AFP PHOTO / JACQUES DEMARTHONJACQUES DEMARTHON/AFP/Getty Images

New York Governor Andrew Cuomodeparts after visiting 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 / Bryan R. SmithBRYAN R. SMITH/AFP/Getty Images

Members of the NYPD, FBI, ATF and other agencies invesitgate the the scene, following a late night 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 / Bryan R. SmithBRYAN R. SMITH/AFP/Getty Images

Members of the NYPD, FBI, ATF and other agencies invesitgate the the scene, following a late night 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 / Bryan R. SmithBRYAN R. SMITH/AFP/Getty Images