def highest_mortality(hurricanes):
  """Find the highest mortality hurricane and the number of deaths it caused."""
  max_mortality_cane = 'Cuba I'
  max_mortality = 0
  for cane in hurricanes:
    if hurricanes[cane]['Deaths'] > max_mortality:
      max_mortality_cane = cane
      max_mortality = hurricanes[cane]['Deaths']
  return max_mortality_cane, max_mortality