Complex sentence: The current structure was destroyed in the 1923 Great Kantō earthquake and rebuilt in 1934 with concrete, and thus survived the Tokyo firebombing of World War II. Unlike many of Japan's historical structures, restoration is being done on Kanda Shrine, and work continues today.
Split into simpler sentences: The current structure was destroyed in the 1923 Great Kantō earthquake and rebuilt in 1934 with concrete, and thus survived the Tokyo firebombing of World War II, unlike many of Japan's historical structures. Restoration is being done on Kanda Shrine, and work continues today.