My landlord refused to fix major things?

My landlord refused to fix major things that got worse in my family's apartment for months. Then gave us that boot. can we sue for months nobody didn't repair the apartment?
Update: rent is 100% paid
Update 2: mold on lath behind drywall and other spots smokes and c02 detectors and more
Update 3: Yes I got a 50 page stack of emails which he states he don"t have to he know the in and outs and many stuff like that
Update 4: the boot was for renovation aka it was too much to ask for a smoke detector
Update 5: to R P how can i get rid of black mold on a wall that is covered by sheet rock are you nuts
3 answers 3