Some pranksters had sprayed isopropyl alcohol on the door of an apartment belonging to their friend. The plan was that when the friend opens it, set the trap ablaze.
The witness opened the door and that started the blaze.
The fire immediately set off a sprinkler in the bedroom, effectively putting out the fire and soaking the remainder of the apartment.
Oxford police are investigating this crime.
Read the article Pranksters ignite door with alcohol, flood apartment'