What should we do about our negligent landlord?

We moved into a house about a month ago and we noticed some serious deficiencies. The place had a laundry room attached to our unit that was filthy to a point of being a fire hazard. We asked that it been cleaned multiple times, so she went and finally swept the lint out from behind the dryers. There were also no fire alarms/smoke detectors, and we had to ask a few times for those to be purchased. My roommate also stated he smelled gas to the landlord and she said that she had the wall heater checked and it was fine. So, we decided to have the wall heaters gas turned off for summer. My roommate almost turned the heater on, as it has been really cold. He wanted to cancel the turn off so that we could use it. I said bundle up. So when the guy came out he said that the wall heater had a detachment that was leaking C02 into the air, and that if we had turned it on there was a good possabiity that we would have caused an expolsion. We contacted our landlord to discuss for putting our lives, and the lives of our 2 dogs in danger(who we crate during the day). We feel like there should be something that they do for being negligent and putting our lives in danger. They have yet to call us back, and it has now been 3 days. We cannot turn our heater on, we put up some smoke detectors. We live in CA. Any ideas, or legal insight. I'm REALLY not happy that they were neglegent to this level!