Soon after lifting off, the pilot's door opened. The helicopter abruptly pitched nose-up and the tailskid struck the ground. The helicopter then abruptly pitched forward and rolled to the right before the main rotor blades struck the ground.
What I find quite remarkable, is that no has yet made mention of the door opening issue... Trying to close the door while in the hover is a basic initial training issue which should never be done
as one can see from this fatal accident.
Forget about the fuel tank/lines that burnt the machine out right now. Deal with the cause of the accident so that others can learn from it.
I was taught and have taught that if the door opened, either land or get some height and speed (depending on where you are in the take-off profile) before trying to close it.