Initial Findings Released in 2nd Ave Subway Explosion Investigation

Holes drilled at this shaft for the loading of explosives have normally been done vertically, allowing the blast pressure to dissipate horizontally. However on Tuesday, rock outcrops, which were being blasted at the top of a future escalator, needed to be drilled diagonally. When the blast occurred, debris hit the underside of the decking concentrated at the southeast corner of the site. The decking lifted and allowed rock to be propelled into the air and onto the street. In reviewing yesterday's incident, we determined that the method used to keep the decking in place above the blast area was inadequate for this type of blast.

The MTA is currently evaluating the following corrective measures to ensure this will never happen again:

As an added measure of safety, an independent safety consultant will be hired to review all the blasting and safety procedures to ensure the community is protected. The contractor, SSK, is conducting an in-depth review of the decking systems that will include anchoring the protective steel panels which prevent rock from exiting the shaft. The perimeter around the blasting area will also be increased, keeping pedestrians further away from the site during a blast. Contractors will also be adding protective mats when they expect the blast pressure to be vertical rather than horizontal.

We are grateful that no-one was injured as a result of yesterday's blast. We also want to apologize to residents, business owners and their employees along the Second Avenue corridor who have already had to endure more than their fair share of inconvenience during this project. The MTA will continue to hold contractors and everyone associated with MTACC's projects to an extremely high standard.

While we are working tirelessly to do what many call "an impossible task" — building a subway in one of the most densely populated neighborhoods in the largest city in America — we will continue to make every effort to be a good neighbor.