This article bears special mention: Into the vault: the operation to rescue Manhattan's drowned internet Hurricane.
Steve [an acquaintance who is a telephone lineman] wrote to note:
"Having a cable vault under a central office flood is a major disaster in the telecom industry. One splice getting wet is a big job. Losing the entire office brings up comments like I didn’t want any days off this year. Having fixed splices like this that have gotten wet I have a good idea what is involved to fix this. It’s a lot of slow meticulous work. If the damage is only in the splice case and the copper is plastic insulated and not paper then drying and replacing the connectors may be all that’s needed (Two guys around the clock 2 or 3 days). If it’s paper insulated then it’s fish out each pair and replace it across the splice repeat 3,000 times (Two guys around the clock for 5 or 6 days per splice).
Most of these cables will have water under the sheath several feet from the opening which can’t be removed or blown out completely. Eventually this water will rot the plastic insulation on the copper and cause various problems, mostly static that will be intermittent. The only way to fix this is to open up the splices and dry those out. You then cut back on the sheath until you find dry cable or you hit the wall, that’s when you start replacing cable.
They describe replacing the copper lines with fibre optic cables in some of the pictures. The future of the telecom industry is fibre but this will require installing switches at all the customer addresses, no small job in itself. First you have to get a new cable into the building (anybody want to dig up the street in front of every customer because that is where the cable duct lines are). Then you have to find space in the building to place the switch. Building owners are being bombarded with requests for space from all the various telecom competitors for space under normal circumstances and they just don’t have space to spare which they aren’t being paid for. After that it’s time to provide power for these switches. Most of the time you need multiple dedicated circuits and UPS’s for these switches. By the way you think maybe all the electricians might be busy?
Bottom line they have a lot of work to do before they are back to normal. The cost for just this one office could easily reach millions of dollars and if somebody said $50 million I wouldn’t be surprised."