A friend told me recently that there was a mini gas explosion at her home because she didn't realise that the gas tank was leaking. Really scary..
Her gas tank was in the kitchen cabinet below the stove, so she couldn't smell anything. I guess if your gas tank is placed in the kitchen instead of in the cabinet, you might be able to smell any gas leakage more easily. Luckily the blast wasn't big, but it was loud enough for her neighbors to hear. She had some minor injuries on her legs, but otherwise she's fine and thank God her kids were in another room.
So lesson for me here is (since my gas tank is also placed in the kitchen cabinet), is to always open the cabinet door and smell smell first before turning on the stove!