My family has owned our building since the 70's. One area that was really dirty was the basement. About 6 years ago, I hired two guys and we did a major cleanup. There were rocks and all types of crap in the basement. The space was still very dusty but it was manageable. Fast forward to this year and I did another major cleanup. I got rid of all the dust and junk(mostly from my tenants) that accumulated over the six years. I even had the floor painted. The basement was looking pretty good. Then, in January/February, whenever it rained, the basement got flooded. I thought it was a burst pipe or some sort of leak from a window. I really had no clue. Then, our super(he organizes the garbage and lets Con Ed in for meter readings), discovered the problem: water was coming right through the electrical panel. I didn't buy it at first but then it made sense because part of our panel had water damage. We made the discovery in early May. I then called Con Ed. It took them three weeks but they scheduled a repair appointment for six weeks after down the road. So, mid July comes and Con Ed came. Indeed, it was the panel. The technician said there was no material to prevent water from coming in. It took him an hour and a half to fill the feed with some sort of material. I should note that I told Con Ed that I thought it was dangerous but they did not consider it so. So, moral of the story is that water can come through your panel and also you need to be vigilant because Con Ed won't send someone out unless it is a true emergency in their eyes.