Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Landed in Emergency Condition; Flight Crew Diverted; General Maintenance Action
Aircraft
When we left ZZZ we had to MEL Pack 1 due to abnormal shutdown. Flight was conducted at FL250 to comply with the MEL. When we leveled off at FL250; Captain and I smelled smoke like wires were burning and saw that smoke a white/gray smoke was coming through the vents. At about that time [the] flight attendant called up and said there was smoke coming from the back of the plane and a loud noise from the pack. Captain and I followed the memory items for smoke/fire/fumes. We then contacted ATC; [requested priority] to descent to the nearest station of ZZZ1. While running the checklist we isolated the problem and the smoke went away. Landed safely in ZZZ1. Flight Attendant did a very good job with handling the situation in the back. The Maintenance met us at the gate and told us that Pack 2 had failed.
EMB-145 First Officer reported smoke and odor operating at FL250 in both the flight deck and passenger cabin with one Air Conditioning Pack already inoperative per MEL. Crew diverted to a nearby airport where maintenance reported the remaining Air Conditioning Pack had also failed.