All of the highways into Wenchuan, and others across Sichuan province, were damaged. This slowed down arrival of the rescue troops. In Beichuan county, 80% of the buildings collapsed. In Shifang, 2 chemical factories were damaged and leaked 80 tons of liquid ammonia. The Dujiangyan Irrigation System, a UNESCO World Heritage Site was damaged. This is an ancient water system which is still in use. The famous Fish Mouth was cracked.