Simplify the following text for a Grade 5 native English-speaking person.
Original: The island of St. Thomas was the hardest hit by the storm , where about 80 % of the homes and businesses were destroyed , including the hospital and the water desalination plant ; five people were killed .
Simplified: The island of St. Thomas was the hardest hit by the storm , where about 80 % of the homes and businesses were destroyed , including a hospital and the water purification plant . Five people were killed .