H. B. Warner was a fine actor, although sound came too late for him to be a leading man. However, whatever part he is given -- here he is the ingenue's industrialist-financier father -- he is head and shoulders above all the other talent. Here his role is intended to be ambiguous, and he delivers -- because up until the very end, you could see him on either side of the law, he plays it that neatly. I cannot say enough about his skill, his charisma, and his command of any scene in which he appears.
Bruce Cabot is rather pleasing as a carefree reporter and Judith Allen is charming as his girl reporter love interest, but the best thing about this film, aside from H. B. Warner, is the tremendous amount of documentary footage involving early 1930s fire engines and burning buildings. The fires are real, from news footage, and are elegantly intercut with scenes on sets. But what really got me was watching the fire trucks running out, sirens blaring, as i tried to figure out in what part of Los Angeles this was filmed.
It was a warehouse district -- the plot called for that -- and we got lucky as we ran the film at half speed to look for business names (Maxwell House Coffee, Gilmore Gas and Oil, etc.) and saw a sign for Imperial Street. Google maps told us that Imperial Street no longer exists, because it has been made into warehouse parking lots now, but it is still on the maps, and right north of it is Los Angeles Fire Station #17 -- where the engine company was located!
Re-running the film, we could trace all the routes, down Santa Fe St., 11th street, by the old train yard -- it is all there. The film footage is not super high-quality, because much of it was shot at night (the title of the film is "Night Alarm," after all) but it is priceless because almost every building in this district, including the fire station, has been torn down and replaced with modern block-structures. Here it is captured, a snapshot in time.
The night club (called a "casino," although no gambling was shown) was not a set either. Where it was, i do not know, but as a location shot it was also a nice treat.
The plot is nifty, the ending is exciting and also satisfactory, so i rated this film as a 7 because of the documentary footage, with an extra point for H. B. Warner's fine performance, giving it an 8 overall.