This is familial negligence...first and foremost.
Without knowing the arrangements between the contractor and the airline, and how that all interlocks, if this woman was compromised enough to get on an escalator with a wheelchair, I simply don’t believe she should have been traveling alone, period.
And it is hard for me to believe her family didn’t know she was compromised enough to actually put her wheelchair on an escalator.
I am sorry for her suffering and her loss.
But not a single member of her family could have gone with her, and entrusted her to strangers, and is now suing them?
I am not inclined to side with her family unless I know more detail. The family will likely win, this will be settled out of court, probably, but I don’t like the smell of it.