A fatal house fire in Monroe is under investigation.  Shortly before 1am today, the Monroe volunteer fire companies were alerted by neighbors of a house fire on Fox Run. The home was engulfed in flames upon firefighter arrival. Most of the blaze was extinguished within 25 minutes. Firefighters located an adult female who had perished inside the home. There were no other civilian or firefighter injuries. Botsford Fire Rescue and Long Hill Volunteer Fire provided mutual aid.  The Monroe and State Police Fire Marshals and Monroe Police are investigating the cause. Crews are remaining on scene throughout the morning.