My question involves landlord-tenant law in the State of: Colorado

I looked carefully at my lease. It does not say who is responsible for maintaining the lawn. I wrote my landlord a letter requesting they either have someone maintain the lawn, or reduce my rent by $100 so I can pay someone to do it. I have asthma & SEVERE allergies so I am unable to mow the lawn myself. They called me & were incredibly rude & said they have always not maintained the lawn & will not even consider helping me. It is a single family house & I am paying several hundred dollars more a month than other people in the area. They have bars on all the windows & doors(firecode violation) & only ONE smoke detector in the entire 3 bedroom & full basement house. A. Because the lease doesn't state I am responsible, does it mean they are responsible by default? B. Should I perhaps call the rental/fire authority & complain so I can get out of my lease since they are breaking the law & putting my life in danger?

Thanks for any advice in this matter.