B757 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Engineer; Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 250; Flight Crew Total 7000; Flight Crew Type 2000
Aircraft Equipment Problem Critical
Flight Crew Took Evasive Action; Flight Crew FLC complied w / Automation / Advisory
Aircraft
Climbing to cruise altitude Right Bleed EICAS Message followed by a Left Bleed EICAS message. Resulting in loss of both PACKS.  Resulting is CABIN ALT warning message.  We began descent to 10;000 while performing QRH procedures.
B757 First Officer reported losing cabin pressure when both pneumatic bleeds failed at FL350.