         return null
       dailyDecayRate = 1.0
       if (@request.query.activeCases + "").toLowerCase() == "true"
-        # TODO: look up disease specific stat
-        caseLengthDays = 14
-        dailyDecayRate = Math.pow(.5, (1 / caseLengthDays))
+        dailyDecayRate = Math.pow(.5, (1 / event.caseLengthDays))
       baseIncidents = []
       constrainingIncidents = []
       event.incidents.map (incident) ->

  # sort events so they are returned in same order as the ids
  events = eventIds.map (eventId)->
    _.findWhere(events, _id: eventId)
  events.forEach (event) ->
    if not event
      return
    if event.incidents

        locations: $not: $size: 0
    else
      query = utils.eventToIncidentQuery(event)
    if (@request.query.activeCases + "").toLowerCase() == "true"
      # TODO: look up disease specific stat
      event.caseLengthDays = 14
      extendedStartDate = new Date(dateRange.start)
      # Incidents from an extended date range are included to determine the
      # initial number of active cases at the beginning of the intended date range.
      # Assuming the half life of all cases is the case length, less than 10%
      # of the cases from before the extended date range would still be active
      # in the original date range.
      extendedStartDate.setDate(extendedStartDate.getDate() - (4 * event.caseLengthDays))
      dateRange.start = extendedStartDate
    if dateRange
      query['dateRange.start'] = $lte: dateRange.end
      query['dateRange.end'] = $gte: dateRange.start
