I recently taxied out behind a Colgan Q400 in EWR and noticed how little area the deicing boots cover the leading edges. Recalling the AE ATR 72 accident in Roselawn ID. back in 1994, it was determined that the ATR's wing deicing boots were inadequate. This resulted in significant ice build-up forward of the aileron hinge line.
Now a significant difference between these two accidents is, the Roselawn accident aircraft rolled on its back whereas this accident Q400 pitched then rolled. This might point to possible tail plane icing.