Hong Kong issued the Black Rainstorm signal as heavy rain swept yesterday evening with golf ball sized hailstones breaking windows, heavy rains flooding subway stations, and thousands of bolts of lightning into the city and surrounding area.

The hail broke part of the glass ceiling at the Festival Walk shopping mall in the Kowloon Tong area, with rain flooding the building. The Observatory stated that more than 70 millimeters of rain had fallen in some parts in less than an hour.