Fire
Fire
[The comic shows the top part of the front page of a folded newspaper. The main headline is the only readable with a photo covering half of the pages below. In the photo a factory is on fire, with sound waves emanating to all sides. There are several sections with unreadable text.] 50,000-Alarm Fire at Alarm Factory


In the United States and Canada, the term multiple-alarm fire is used to categorize the level of response to fires by local authorities, for instance how many units responded to the alarm. The range typically only goes through a small number of levels: typically a one-alarm fire, two-alarm fire, and three-alarm fire, perhaps up to five or six alarms in some cities, though a ten-alarm fire did occur near where Randall lives two months before the comic.
In the comic, a newspaper front page is shown with its cover story reporting a "50,000-alarm" fire, with a picture of a factory on fire. The humor lies in the unusual use of the term.  Instead of indicating the severity of the fire, the number merely indicates the number of alarms being manufactured or stored in the factory at the time of the fire. As indicated by the sound waves, or agitrons, shown in the image, at least some of those alarms appear to have been set off. It is unclear what the causal relationship between the alarms and the fire is.  The presence of fire might have activated those alarms (e.g. if they are smoke detectors), the sounding of alarms might have caused the fire to start (e.g. due to workers' attention being diverted from other critical operations), or they might be unrelated events that happened at the same time.
The title text mentions the musician Billy Joel being detained briefly as a suspect for the fire. But he was quickly released, likely because he didn't start the fire , which is a reference to his song " We Didn't Start the Fire ". In other words, Billy Joel's claim that he is not responsible for the fire at the alarm factory has been taken seriously enough for him to be released. Also, the reference is humorous because it compares the literal fire depicted in the factory to the metaphorical fire in people's hearts, in the song. (Or just ignores the fact that the song's fire was metaphorical, for the sake of the joke.)
The incident where Billy Joel got arrested for arson was earlier shown on a similar folded newspaper with only one line of text visible next to an image. This was in comic #4 of 821: Five-Minute Comics: Part 3 .
This all fits together as the cover of the single is also a newspaper page with a picture of Billy Joel beneath a headline which is the title of the song. The column of text to the right of the picture is readable here. It is not easy to read it through as some of the text continues outside the image. (The text is a section of the lyrics for the song starting from "Richard Nixon" after the fourth chorus continuing in to the next chorus).
The lyrics of the song is also mentioned in 1775: Things You Learn .
That Billy Joel was released is also obvious since he has also sung the song An Innocent Man , where he sings I am an innocent man, Oh yes I am .
[The comic shows the top part of the front page of a folded newspaper. The main headline is the only readable with a photo covering half of the pages below. In the photo a factory is on fire, with sound waves emanating to all sides. There are several sections with unreadable text.] 50,000-Alarm Fire at Alarm Factory

