My property has been damaged because of construction of gas company. How I can sue them?

have two story business property. The guys from gas company made this huge holes right in front of my property last monday and it has been done yet. They cover this hole with a metal plate. The problem is whenever cars passing by my building shakes so bad. I found cracks and existing ones got worse. I called them to ask to do something. They put this little wooden block but nothing helped. I think I need to prove that how bad it shakes because of the construction but I dont know where do I have to start. Please help me.

Make videos or photos of all of the walls NOW and record the date and time the photo was taken. A video camera that shakes when cars cross the plate would be good. When they finish the work, repeat the same with no cracks or shaking camera. It will help if you have friends and customers that can testify that there were no cracks before the work started and described what was happening while the plate was there.

If you can find a professional engineer to look at it and analyze the stress the hole is putting on the building, that will help a lot.

If you can make the evidence clear and convincing enough that they know they will lose the court case, they will fix it to avoid the additional cost of the legal proceeding.