Roads surrounding an abandoned building in Port Chester were closed Tuesday morning as officials investigated what caused it to go up in flames.

Investigators were back on the scene with several cadaver dogs, as well as Acorn, the arson dog.  

The fire was seen shooting through the roof on Main Street Monday morning and quickly spread to a neighboring building.

The fire also caused delays on the nearby Metro-North New Haven line, but service is now back to normal.

South Main Street between Westchester Avenue and East William Street is closed as police check the building for damage.

Officials say there are plans for the whole block to be torn down and turned into a mixed-use development.

They hope it will give the downtown area a face life and draw in more commuters.