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Good morning.



Here’s what you need to know:

• Learning from past calamities.

Hurricanes Harvey and Irma have revealed some encouraging news: The U.S. appears to be improving its response to disasters. For all the suffering and damage, the storms were less deadly than had been feared, with about 85 killed in Texas and Florida.

The change has been driven partly by two of the century’s defining disasters in the U.S.: the terrorist attacks of Sept. 11, 2001, and Hurricane Katrina four years later.

On Thursday, President Trump will visit Florida, where millions remain without electricity. We look at why it could take weeks to restore power.