The highrise in Madrid burned for two days and remained standing.
The highrise in Madrid remained standing only because the portions that survived WERE REINFORCED CONCRETE and therefore essentially impervious to fire. All the portions of the tower that relied solely on steel frames did in fact collapse ... and fairly early on during the fire. Why do you find it necessary to hide these fact from the folks here at FD4UM?
Got a propane torch? If so, light it up and, if you have a basement, put the flame to a wall and see what happens. You might want to wear eye protection.