Flight Crew Air Transport Pilot (ATP)
Workload; Time Pressure; Troubleshooting; Distraction; Confusion
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor; Inflight Event / Encounter Weather / Turbulence
Aircraft Equipment Problem Dissipated; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Landed in Emergency Condition; Flight Crew Took Evasive Action; General Declared Emergency
Aircraft; Human Factors; Weather
During arrival/descent we experienced 'L Bleed Duct' Warning message. First Officer was pilot flying and I ran the QRH. As described in the QRH the bleeds closed and the cabin altitude began to climb at a nominal rate. We were at approximately FL240 at this point and requested expedited descent.  At that same moment continuing the QRH; a flight attendant called and said there was smoke in the cabin; apparently emanating from the rear lavatory and the smell was very bad. We immediately declared emergency with ATC [for expedited clearance to our destination]. ATC was notified of the nature of the emergency; bleed issue and smoke in the cabin. QRH for Smoke/Fumes removal was executed. Further communication with the flight attendants indicated that the smoke smell had dissipated and that it was essentially smell; not actual visual smoke. This appeared consistent with the indications in the cockpit and also that we experienced no smell or smoke in the cockpit during the entire event. I told the flight attendants to prepare for an emergency landing shortly as a continuing precaution; and then briefed the passengers. Also notified ATC that we had the situation stabilized. An expedited but uneventful ILS was completed to landing. Upon clearing the runway; we had the ground emergency units inspect the aircraft to verify our condition. They reported nothing abnormal; we then proceeded to the gate. There was not sufficient time to notify Dispatch during the incident given the close distance to the airport and cockpit workload. Dispatch and Maintenance were notified on ground as soon as it was practicable. Following the event the flight attendants reported not feeling well.Cascading deteriorating conditions involving multiple QRH procedures during a high stress/workload could easily lead to confusion. Things can become a blur and it is important to force yourself to slow down and resist the tendency to go too fast especially when navigating multiple and linked QRH procedures.
There were several threats such as high workload environment; multiple QRH procedures; weather in and around the destination was IMC which increased the workload factor in the emergency.Every emergency is different but I think you should always take a step back and analyze the situation instead of just reacting. Furthermore; I also think you should always evaluate your performance after the emergency to improve yourself as a pilot; which is what I'm always striving to do.
During descent a CRJ-900 EICAS alerted L BLEED DUCT and about the same time a flight attendant reported a bad odor and smoke from the aft lavatory. An emergency was declared; the QRH completed and the flight proceeded to the nearby filed destination.