Phase 2 of the investigation begins Thursday at the site of a deadly explosion and fire at JJ's Restaurant on the Country Club Plaza in Kansas City, Mo.
Authorities plan to dig up the street outside the restaurant on the plaza.
Investigators are looking to see if there are more utility lines buried there, and where those lines might lead.
This is all part of the investigation that now spans three agencies – the ATF, Missouri Gas Energy and the Missouri Public Service Commission.
Heavy equipment was expected to move in Thursday to dig up a part of the street in front of where the restaurant once stood.
The Feb. 19 explosion killed one JJ's employee and injured about a dozen other people.