According to Hannah Kasulka, during the shooting of the pilot episode, when she and Brianne Howey took the elevator in the hotel in which they were staying, it would sometimes stop on the 13th floor, even when they had not pressed the button for that floor and when nobody had called the lift to the floor.
The church seen in the opening sequence of the pilot is located at 911 W. 50th Place, in Chicago's Back of the Yards neighborhood. As of 2016, the church is home to the Ebenezer House of Prayer, but was built in 1910 to serve the parish of St. John the Baptist. The parish was founded in 1892 to serve French-speaking people living in the area. The words "Eglise St. Jean Baptiste" appear on the frieze above the Corinthian columns that frame the entrance, as seen in Google Street View. The French name of the church is too blurred to read in the opening sequence, but street signs showing "50th" and "Peoria" can seen shortly after the action jumps to Chicago.
The internet article says that Karris and Merrin died on the night of March 13.