According to the Canadian Forces crash investigation, a gull hit the angle of attack probe, then entered the left hand engine intake and
was ingested by the engine, causing serious damage to the engine. The aircraft reached a maximum altitude of approximately 3700 MSL (1700 AGL). After the aircraft descended through 3000 MSL, the crew successfully ejected. One crewmember was seriously injured and the other received minor injuries. The aircraft was completely destroyed when it crashed about seven seconds later in a farmer's field.
Video from just before ingestion until aircraft impact
Additional information
Canadian Forces crash investigation page
Accident investigation report
Initial report summary (2004)
Report summary update (2007)