A few thoughts.
The crane is too damaged to venture into a large scale rescue of the crane. The structure is to unreliable. It is going to be a dangerous operation because the steel is under stress it was not intended to be. So, when further disturbed there is a lot of tension that will be relieved when it is manipulated. The stress on the steel when relieved can kill people.
That is to begin with.
I see this structure as a toppled tree. The safest way to remove this is through removal of small sections. I am talking about 8 to 10 foot sections. That means cutting through the steel to remove the dangling structure.
I see the dangling section of the crane as scrap metal. I don't think there is much choice. If there is a city that understands collapsed structures it is New York City with the dismantling of the twin towers. However, the structures in Lower Manhattan were crashed to the ground and mostly without unpredictable stress on steel.
In thinking about the subways, there are so many electrical structures involved it will be like working in a mine until the flood waters are gone and the structures dry out. Electricity is water loving and it will travel a long distance if released. Electricity is fluid as water is. It will travel along the waters and can cause deaths through the entire length.
This is a horrible example, but, it will work to illustrate what I mean.
A friend has a house on a pond nearby. A severe storm, called a 'blue lightning event' occurred. One stroke of lightning hit the pond. He was at his dinner table when it occurred. He stated the water lit up briefly and what followed next was out of The Twilight Zone. Every duck, goose and swan on the water was thrown into the air. The next morning after the storm passed and the electricity was knocked out to the entire community, which wasn't repaired for five day; the wildlife folks were dispatched to remove all the dead birds.
Electricity and water cannot be mixed without disastrous effect. That is the reality New York City has to work with.
Additionally, while animals such as rats won't necessarily survive the flood, there are others that love water including poisonous snakes. Some may have been pets, especially large Boas, etc. It will be best to have workers be aware of this possibility and wear dense protective rubber suits if venturing into water. However, suits can tear if caught on something unseen, too.
To say this is a difficult situation is an understatement.
