More than 10,000 travelers are stranded at an airport in southwest China’s Sichuan Province.

Dense fog enveloped parts of Chengdu City, reducing visibility, delaying 45 outbound flights, and causing three inbound flights to land on alternative fields.

The fog began appearing at around Four Monday morning, and the airport issued an alert for massive flight delay about two hours later.

It closed one of two runways, and made arrangements to comfort the stranded travelers, including providing water and food, and transferring or refunding tickets.