That merely states 'The Congress shall have Power … To make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof.'
Congress has the power to pass laws which are necessary and proper to carrying out the powers the states granted it in the Constitution. That doesn't mean that it has the power to pass any laws whatsoever, and even if it did the Tenth Amendment would supersede it.
The Constitution simply doesn't grant the United States general power to deal with natural disasters, so there is nothing necessary and proper for the federal government to do.
Congress has the power to pass laws which are necessary and proper to carrying out the powers the states granted it in the Constitution. That doesn't mean that it has the power to pass any laws whatsoever, and even if it did the Tenth Amendment would supersede it.
The Constitution simply doesn't grant the United States general power to deal with natural disasters, so there is nothing necessary and proper for the federal government to do.