B777 First Officer reported an engine malfunction st the start of the takeoff roll. The takeoff was rejected and the aircraft taxied to parking.

Narrative

For this flight; I was the FO and Pilot Monitoring. Start and taxi normal. Cleared for takeoff on Runway XX; from Taxiway 1. The Capt taxied us onto the Runway; aligned the nose. While holding the breaks; he pushed up the throttles to allow them to stabilize. The left engine was slow to spool up but reached a stabilized setting. The Captain then released the breaks and pushed up the throttles and called to check thrust. I confirmed thrust was set. Shortly after; it felt like we hit a divot in the concrete followed by a loud bang; slight shutter to the right; audible 'Engine Failure'; and master warning annunciation and EICAS. We were around 40 kts when this occurred. Pilot Flying initiated the rejection while I called Tower. The Relief Pilot made the 'remain seated' PA. We cleared the Runway and sat on a parallel taxiway while we ran checklists and made radio/phone calls. Maintenance Control said they saw the engine failure in their system. Check-in with the FAs validated the loud bangs and they confirmed no other visual issues with the engine. The engine remained running and only indicated an issue when we began taxing to the hard stand. The EGT would spoil up very quickly and very high; especially in contrast to the left engine. We parked at a hard stand; shutdown and Maintenance began looking into the issue while we coordinated to get the Passengers back to the terminal. Capt did a fantastic job delegating duties and keeping everyone informed. Training definitely kicked in as designed.