CRJ-700 SUFFERS TOTAL LOSS OF PRESSURIZATION DUE TO ENGINE BLEEDS CLOSING.

Narrative

CLBING THROUGH FL230 WE RECEIVED A RED 'L BLEED DUCT' WARNING CAS MESSAGE. WE REFED THE QRH AND IT TOLD US TO WAIT 60 SECONDS TO SEE IF MESSAGE WOULD GO AWAY; WHICH IT DID NOT. WE ADVISED ATC THAT WE WERE GOING TO LEVEL OFF AT FL250 TO TROUBLESHOOT A PRESSURIZATION PROB. WHILE RUNNING THE REMAINDER OF THE QRH; THE RED CAS MESSAGE WENT TO AN AMBER 'L BLEED DUCT' CAS MESSAGE. WE WERE GIVEN A DSCNT TO 13000 FT BY ATC AND WERE COMING DOWN AT GREATER THAN 3500 FPM. THE CABIN THEN COMMENCED TO CLB AT A GREATER RATE WHEN THE REMAINDER OF THE AMBER DUCT QRH WAS BEING ACCOMPLISHED. ATC DIDN'T APPEAR TO REALIZE THE URGENCY OF OUR ORIGINAL REQUEST FOR 10000 FT SO I ELECTED TO DECLARE AN EMER TO CONTINUE OUR DSCNT TO 10000 FT. WE STATED OUR NECESSITY TO DIVERT TO ZZZ AS OUR NEAREST SUITABLE ARPT TO CONTACT OUTSTATION MAINT TO LOOK AT OUR PLANE. WE DID MANAGE TO KEEP THE MASKS FROM DEPLOYING ALTHOUGH IT WAS CLOSE. WE DID GET A CABIN ALT WARNING MESSAGE. THE FLT ATTENDANTS WERE ADVISED OF THE SITUATION AND AN UNEVENTFUL LNDG WAS MADE. THE ROOT OF THE MECHANICAL WITH THIS ACFT WAS A DUAL CLOSURE OF BOTH BLEED SHUTOFF VALVES FROM BOTH ENGS TO THEIR RESPECTIVE PACKS. WE HAD A TOTAL FAILURE OF THE PNEUMATIC SYS DUE TO THE FACT THAT BOTH SHUTOFF VALVES CLOSED SIMULTANEOUSLY. THERE WASN'T ANY CHKLIST PROC LEADING FROM A SINGLE RED 'L BLEED DUCT' EVENT.