Some years ago. The Saturday night of the July 4 weekend. BA from Phoenix to Heathrow had tech problems appearing after we boarded. Off loaded us, and all the ground staff stayed on, handing out water ( and champagne and sandwiches in First Class lounge!). Re-boarded and the had an engine refuse to start. Off load again (it was cooler in the terminal) and the ground staff were getting worried - it's obviously not easy at 10pm on the July 4th weekend Saturday to suddenly find hotels for pax from a full 744. They were still good tempered, sympathetic, handing out the water, kept the lounge open. We reboarded about 2245, and got away, to a BIG sigh of relief from everyone - except one young CC member with whom the CSD was heard to have words after she was moaning to another CC member in front of pax about having to go into discretionary time. But BA staff did a first class job on that occasion. I do just wonder if it wasn't helped by the fact that they're a long way from Waterside!