National Transportation Safety Board investigators are leaving the site of the East Harlem building explosion.
The NTSB released a preliminary report that says that investigators found gas leaks along the 8-inch cast iron gas main on Park Avenue.
However, the report does not say that those leaks actually caused the explosion.
Eight people were killed and dozens were injured in the blast a few weeks ago.
The investigation will continue in Washington D.C., where more pipe tests will be done.
The NTSB says investigators will also examine leak surveys and maintenance records for the gas main.