Consider the following statements
1. Iron and steel industries developed around lake Michigan in U.S.A. due to the availability of good quality coal.
2. Pittsburs-Young stown area is the leading producer of steel in U.S.A.
3. The Lorraine area in France is significant for steel production.
4. The south Manchurian region accounts for nearly 60% of China's pig iron production.
Which of the above statements are correct ?