There will be a whole host of errors that have led to this being such a tradegy.
The investigation will be very interesting.
I think having two escape routes at opposite ends of the building has to be a 'must'. Impossible to retrofit that tho!
Also like a PP posted people are their own worst enemies - not bothering with smoke alarms (not that you should rely on your own one in a tower block, there should be a central one) leaving things in corridors, propping open fire doors, replacing doors, breaking risers, storing stuff in electrical cupboards, buying dodgy as fuck electrical items cheap from China etc.
These blocks need to be managed better - fire inspections weekly (binning anything in corridors), access to apartments for fire alarms/fire testing etc a condition of your lease with building management having keys to all apartments.
There should be 23h building management on site.
I don't see why sprinklers weren't installed in the refurb (need to be 'manually' set off by fire service or something or building management rather than linked to fire alarm in case of false alarms).
I would expect there to be a central fire alarm system in all the corridors that was super loud.
Fire doors in corridors should be automatically held open and the holding mechanism releases on a fire alarm because otherwise people just prop them open so are useless.