Alerted by a loud bang and an ENG DEGRADED EICAS message the flight crew of a CRJ-700 shut down the right engine; declared and emergency and diverted to the nearest suitable airport.

Narrative

While in straight and level cruise at FL400 both pilots and the Number Two Flight Attendant heard a bang followed by a rumble. Both pilots scanned the instruments and noted the right engine N1 and N2 decreasing and fluctuating and the ITT increasing accompanied by an ENG DEGRADED (R) EICAS message. We retarded the right thrust lever to idle and monitored the instruments but after noting that the ITT was still increasing the right thrust lever was moved to shut-off and the engine shutdown procedure was applied. We declared an emergency with ATC and requested a descent.Since the Flight Manual directs us to land at the nearest suitable airport under these circumstances and we were still 256 NM from our destination we elected to divert to an airport which was only 131 NM away. We notified the Flight Attendants and passengers of our situation. We executed an uneventful single engine ILS to Runway 23R and were met by CFR. After the Fire Department took a look at our right engine they terminated the emergency and we taxied the aircraft to the terminal.