why couldn't the deceased escape the fire?

Possibilities include:

• They were dead already;
• They were intoxicated due to alcohol +/- drugs;
• They were old +/- infirm;
• They were immobile for some reason;
• They were rapidly overwhelmed by fumes/ smoke due to poor physiological reserve e/g/ coronary artery disease or chronic obstructive pulmonary disease;
• There was insufficient time to escape the fire due to the nature of the fire itself e.g. a flash fire or explosion;
• There was panic/ confusion;
• Escape routes were obstructed (deliberately or accidentally); or
• The deceased was in an unfamiliar environment (and did not know where the escape route was)