Firefighters responded to the three-alarm blaze in the 500 block of North Lumber Street at around 2 a.m.
Officials were investigating what caused the fire, which started in a detached home on the block but then spread to a pair of attached homes next door, LehighValleyLive.com reports.
No injuries were reported and it's not clear how many were displaced, though the American Red Cross said it is assisting at least one of the families affected.
Allentown Fire Department was not immediately available for comment.
Click here for the full story from LehighValleyLive.com.
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