It is so disappointed to hear this news as a road engineer. Flight delay happened in USA because of the high temperature deformation in the airfield pavement. Extreme heat over the weekend is also to blame for a US Airways flight getting stuck in the tarmac at Reagan National Airport.
The attached picture posted on Reddit.com shows of the tires stuck into the softened asphalt runway tarmac. About 35 passengers and three crew members on board had to get off the plane so a tow vehicle could budge the jet out of the rut. The incident happened on Friday (13-07-2012) when temperatures were in the upper 100C.
The Charleston, South Carolina flight eventually took off after a three hours delay.
Source: AOL Travel UK