A gas explosion occurred in the afternoon of March 26, 2015 in a building located at 121 Second Avenue in the East Village neighborhood of Manhattan, New York City, United States.

The explosion caused two deaths, injured at least 19 people, four critically, and the resulting fire completely destroyed three adjacent buildings at 119, 121 and 123 Second Avenue between East 7th Street and St. Mark's Place.

[1] In the days before the explosion, workers had been installing a new four-inch (10 cm) gas line to service the apartments at 121 Second Avenue.

[2][3] On the day of the explosion, Con Edison investigators had inspected a new gas-pipe installation at 121 2nd Avenue, which remained turned off, and left about 2:45 p.m.

When the contractor in charge of the work and the landlord's son opened the basement door, an explosion occurred, and the front of the restaurant was propelled across the street.

The first emergency calls were received at about 3:17 p.m. New York City mayor Bill de Blasio said, "The initial impact appears to have been caused by plumbing and gas work that was occurring inside 121 Second Avenue.

[13] Officials focused on plumbing and gas-line work in the 121 2nd Avenue building to determine whether a gas line intended only for the restaurant on the first floor was inappropriately tapped.

[15] On February 11, 2016, Cyrus Vance, Jr., the New York County district attorney, announced the indictment and arrest of five people in connection with the explosion, including building owner Maria Hrynenko, Hrynenko's son Michael, a plumber who had used his city license to allow others to perform work for him, the unlicensed plumber who did the work and a contractor, Dilber Kukic.

Andrew Trombettas, a plumber who sold his credentials to Ioannidis, pled guilty to lesser charges in January 2019.