Practical joke on flatemates need advice what to do?

did a practicle joke on housemates at un with a friend, we but flour all along the halls corridor put a bag of flour above the kitchen door so when someone opened door it would go on them but a gl of water on edge of side with water in and put bag over it and filled the hover with flour hahah. the practicle joke worked in the morning perfectly and it was hilarious the fell into all the traps and and then got hover out then got covered in flour hahahahah. however they took it a different way and were really really angry one of my flatemate was slagging of my friend and was quite nasty i was shocked we cleaned it up within about 10 mins but now all my flat mates hate me and i mean really detest me also on the same night the fight extinguisher came of wall and there blaming us for it when we did not do it. what do you think of this. it was only a practicle joke and was quite funny and yet they were horrible and very nasty and quite offending towards us after it.