On Sept. 20, 2017, Hurricane Maria barreled across Puerto Rico with winds of up to 155 miles per hour and battering rain that flooded towns, knocked out communications networks and destroyed the power grid. In the rugged central mountains and the lush northeast, Maria unleashed its fury as fierce winds completely defoliated the tropical forests and broke and uprooted trees. Heavy rainfall triggered thousands of landslides that mowed over swaths of steep mountainsides.