You point out one of many reasons but aged and non maintained electrics is one of the main ones, the ladders are obviously leaning on a damaged cable of some sort possibly an old install as i assume RCD protection wasn't present and years of going in and out of the loft has probably taken its tole on the cable until this most tragic of accidents occurs
The nature of Electricity means your everyday joe blogs forgets its need for maintenance, if you have a gas leak your instant response is to get a pro' in to sort it out because everyone knows the risk but Electricity has a natural complacency when using it, if a fuse blows its common for the owner just to replace the wire or reset the device without questioning the reason yet like gas it should command the same concerns especially on older installs.