The man's three-year-old grandchild was in Denver, US, and was due to be taken off life support ahead of donating his organs to 25 people.The man was in Los Angeles on business, and his wife had arranged for him to transfer at Tucson airport, Arizona, onto a flight bound for Denver to be with his daughter.

Yet, despite arriving at the Los Angeles International Airport two hours before his flight was due to depart, lengthy check-in lines meant he faced a race against time to board on schedule.

But in an act of extraordinary kindness, the pilot delayed his plane by 12 minutes so that the man would be able to board it to be able to say goodbye to his grandson, the Daily Mail reported.

According to a letter written to travel blog Elliott.org by the man's wife, he was greeted by the pilot and ticketing agent with the words: "We held the plane for you and we're so sorry about the loss of your grandson."

The letter read: "As my husband walked down the Jetway with the pilot, he said, 'I can't thank you enough for this'. The pilot responded with, 'They can't go anywhere without me and I wasn't going anywhere without you. Now relax. We'll get you there. And again, I'm so sorry'."Commenting on the compassion of its employees, a spokesperson for Southwest Airlines said the airline was proud of the pilot's behaviour.