At 7:20 a.m. ET on Dec. 11, a 27-year-old man detonated a pipe bomb in the walkway between two of the busiest subway stations in Manhattan. Four people suffered minor injuries as a result of the blast, and the suspect — identified by police as Brooklyn resident Akayed Ullah, an immigrant from Bangladesh — was taken to Bellevue Hospital with burns and cuts to hands and abdomen. It is believed that the individual was acting alone, and the bomb failed to detonate fully.

New York City Mayor Bill de Blasio labeled the incident an "attempted terrorist attack" in a press conference about two hours after the suspect was taken into custody. The NYPD said that the pipe bomb that Ullah detonated was an "improvised low-tech explosive device," with John Miller, NYPD deputy commissioner for counterterrorism, commuter told Newsday [1]. Officials have not confirmed a motive or any connection to any larger terrorist group at this time.