As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STRONG BURNING RUBBER SMELL IN FIRST FOUR ROWS OF BUSINESS CLASS. DIVERTED TO PHL. A DETAILED CHECK OF THE AREA WAS ACCOMPLISHED AND NO PROBLEMS WERE FOUND. A SEARCH OF THE AMIS DATABASE HAS BEEN ACCOMPLISHED AND NO FAULTS COULD BE ATTRIBUTED TO THIS EVENT. THE AIRCRAFT HAS CONTINUED TO OPERATE WITHOUT FURTHER INCIDENT.