We had quite an interesting night last night. We always close the nest up during the day, when we leave, just in case a rain shower would blow through. If Mallery can not come with us, we turn on the air while we are gone. The last two days when we have returned to our nest, I could smell something that smelled like rotten eggs. Joe could not smells it, but check the stove to make sure the pilot light was not blown out. I checked the bathroom, but it didn't smell in there. After assessing the situation and not finding anything, we'd open the windows and the smell would disappear and I would forget about it. Last night Joe shut the windows in the front room, and said good night.(We keep the bedroom windows open, but close the front room ones in case of rain). Within a few minutes, I started to smell the rotten egg smell again so I told Joe about it, and being a little frustrated with me, came out again and checked everything, and said everything looked fine, then went back to bed. I checked the bathroom once again, and I didn't smell anything. I opened all the windows, exhaust fans and turned on all the fans. I got on the internet and googled egg smells in RV's. A few minutes later, I went back into the bedroom and asked Joe, before he fell asleep, if maybe we should turn off the propane gas, just in case there was a leak. To appease me he got up again, put his clothes on and went outside to shut off the propane tank. Before going to bed he said, he didn't know what else to do and if it would make me feel better, I could call the fire department. With the tank turned off I felt better, and decided everything would be fine till the morning when we could call someone, to check for leaks. I stayed up and continued to google and research the problem. I read, that if you smell rotten eggs, you are to open all the windows, and you need to leave your RV and call the fire department. I thought about it, but could not smell anything anymore, so I decided to go to bed with all the windows open, exhaust fans on and regular fans running. After all, Joe did turn the gas off! I got into bed and laid there for a moment and then I could smell rotten eggs again. The propane tank is directly below my bed, and the window was open and we had the propane tank door outside open. I started to think maybe, the tank outside had a hole in it and it was leaking outside & into my window. All I knew was that it smelled strong in the bedroom as the fan blew the smell around. I got up, put my clothes on, got Mallery, and came out to the front room. I didn't smell it anymore in the front room, but decided to call the fire department and go out to the car till it was checked out. Mallery and I sat out in the car for about 10 minutes when a older gentlemen drove up in a truck and ask if I was the one who called. I reply, I had, and he said the fire department would be here soon. He than put on his orange vest, and a helmet that had a front shield on it. He asked if everyone was out of the RV, and I replied my husband was in bed. He said," your husband is still in there", with a surprised look on his face and I told him that Joe didn't smell anything and wasn't worried about it. He hopped into his truck and drove halfway down the block and turn on his flashing lights. A few minutes later the fire truck drove up( sirens off) with their flashing red lights. It was 1:00 AM, and five firemen jumped out of their truck. I told them the situation and that my husband was still in bed. As I approached the front door to tell Joe the fire department was here, he met me at the door. Later the next day, he told me he had never fallen back to sleep, and saw the red flashing lights out the window. One fireman went in with is gas detector, as the others went over to the tank to make sure it was turned off. After a few minutes, we were told there was no gas detected, but maybe it had all ventilated out the windows, since the tank had been turned off. They told us not to turn on the propane till tomorrow, and if the smell returns, to have someone check out the RV. We went back to bed, and I didn't smell it anymore, and we both fell asleep. I awoke to the smell of rotten eggs. Joe was not in bed. I called for him and asked if he had turned on the propane. He was closing the windows, because it was a chilly night and he wanted to warm up the place. He answered no, but he was smelling something now himself. He told me, the black water tank was full and thought maybe that's what I had been smelling. I said, well it is worth a try. He dumped the tank and immediately, the smell was gone. Joe then proceeded to tell me that he had been watching the tank and was planning on dumping it today. Because he couldn't smell what I was smelling and because I kept saying I thought it was gas, he didn't get the connection. I'm glad we have learned this lesson, and this won't happen again. I am just sorry I had to wake five firemen and a volunteer up, because of a toilet full of rotten eggs. Yes we eat eggs every morning. I still don't understand why the smell was not strong in the bathroom and if anyone knows, please let us know!