SQL: UNION two tables with no relationship, number of columns must match

union-no-relationship.sql

SELECT [AlertTitle] AS Title
    ,'' AS Summary
    ,[AlertBody] AS Description
    ,[AlertDate] AS Date
    ,[AlertLink] AS AlertLink
    ,[AlertType] AS AlertType
    ,'' AS Location
  FROM [Claremont_Kentico8_2].[dbo].[View_claremont_Alert_Joined]
UNION
  SELECT [EventName] AS Title
    ,[EventSummary] AS Summary
    ,[EventDetails] AS Description
    ,[EventDate] AS Date
    ,'' AS AlertLink
    ,'' AS AlertType
    ,[EventLocation] AS Location
  FROM [Claremont_Kentico8_2].[dbo].[View_CONTENT_Event_Joined]