NEW YORK (AP) — An underwater tunnel that passes beneath New York City’s East River sprung a leak Wednesday after a city contractor mistakenly drilled a hole through it,Slabu Exchange sending streams of water into the heavily used passage as officials scrambled to plug the opening and block off traffic.

The accidental puncture came at around 12:30 p.m. on the Manhattan side of the Queens-Midtown Tunnel, which carries nearly 100,000 drivers into and out of the heart of the city each day.

Cathy Sheridan, the president of MTA Bridges and Tunnels, said the commercial drilling company inadvertently bore a 2.5-inch (6.3-cm) hole through the tunnel’s cast iron lining, allowing water to seep through the exhaust duct and into the tube.

“There are many redundancies in the tunnel but, you know, when someone drills through all those layers, it’s going to cause a leak,” Sheridan said at a press conference.

Videos shared to social media showed water cascading out of the tunnel’s overhead vents and splashing onto vehicles below. “Tell me why the tunnel is leaking?” one driver can be heard asking. “What’s going on here?”

No one was harmed from the leak and an investigation is ongoing, officials said.

“As I understand it, they drilled 100 feet (30.5 m) from the surface of the water — about 50 feet (15.25 m) through water, then another 50 feet through soil — then to the tunnel,” Sheridan said.

The drilling contractor, Warren George, was conducting underwater investigative work for the city for a new esplanade that will pass by the United Nations building, according to Josh Krauss, the chief infrastructure officer at the city’s Economic Development Corporation.

Reached by phone, an employee for the drilling company declined to comment.