Complex sentence: Examination of debris suggested that the fire burned through the floorboards in the cockpit, resulting in structural failure and damage to cables underneath the instrument panels; however, it was just as likely that the crew had also become incapacitated by smoke and fumes.
Split into simpler sentences: Examination of debris suggested that the fire burned through the floorboards in the cockpit, resulting in structural failure and damage to cables underneath the instrument panels. However, it was just as likely that the crew had also become incapacitated by smoke and fumes.