Methane has no odor, true. Mercaptan is added to provide a warning property, due in large part to the disaster you cite.
However, as it comes from the ground there is an odor. The odor varies with the formation that it comes from. Sometimes crude oil, sometimes sulfur compounds and sometimes aromatics and heavier alkanes. You can smell it. Flowback brine, sludge and scale in the pipes and vessels stinks.
And BTW the added odorant can ‘fade’ and lose its warning property. That may be due to olfactory fatigue. Thus do not ignore a smell of gas even if the odor goes away.
When I came back from VN in 1974, my brothers and I bought a Gas Furnace my dad, ran about 1500 foot of piping off an old oil well to it with about 13 lbs. of pressure and it heated his house for FREE for years. I went to Africa for a while and was told State officials tried to shut down the operation because it didn’t have a warning smell. My bros. rigged something up that would put a rotten egg smell in the house if there was a problem. The lawsuits went on until Dad died and Mom died. After that my sister’s kid took the old farmhouse down and built a new place with the same hook up. Since there was no record of what the new house used for heating, they haven’t been back and he’s using the same well, same hook-up and laughing his ass off. The State (or whoever) spent a ton of money and we never spent a dime defending my Old Man’s right to HEAT HIS OWN HOUSE.