Yunnan Airport Group Co., Ltd has issued a public letter of apology to around 20,000 passengers who had to stay at the airport due to bad weather on Jan 3, chinanews.com reported.

In the letter issued on Monday, the company said that 440 flights out of 716 had to be cancelled on Jan 3 due to thick fog at Changshui International Airport in Kunming, capital of Yunnan province, which stranded around 20,000 passengers at the airport. The company said that its emergency plan was flawed and it failed to provide a proper service.