As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 7849 - IAD-YYZ - EN ROUTE FROM IAD TO YYZ IN CRUISE FLIGHT AT FL260, HEARD A "POP" NOISE AND THE AIRCRAFT PULLED SLIGHTLY TO THE RIGHT. THEN NOTICED THAT ENGINE NR 2 WAS SPOOLING DOWN AND THERE WAS AN "E2 OUT" MESSAGE ON THE EICAS. RAN THE QRH, STARTED THE APU AND ATTEMPTED AN APU STARTER ASSIST AIR START BUT THE ENGINE DID NOT ROTATE. CONTINUED WITH THE QRH PROCEDURES, SECURED THE ENGINE, DECLARED AN EMERGENCY AND DIVERTED TO BUF. MAINTENANCE REMOVED AND REPLACED NR 2 ENGINE.