OK, So ????? ???? ???…
Let me try to add my own two cents…
If one would indeed leave a mazik, as noted above, big flame, flamables etc. that would constitiue one’s own doing. Same with the case Sam2 brought, breaking the law.
However, I don’t think leaving on a hot plate constitutes one’s own doing. The natural process is for no fire to occur. The lack of smoke detectors, in my opinion, DOES NOT make it a circumstance or place of sakana. It’s not a fire alarm or lack of it that causes fire, it’s the source that causes it.
Furthermore, as I’ve heard, if someone makes a ‘chshbon hanefesh’ from that to protect himself, buy 25 smoke detectors, CO detectors (2.5 @ room) etc. with a “it’s not gonna happen by me” atitude, he DAVKA runs into the danger of being ?”? proven wrong by HaShem. We are supposed to do our Hishtadlus on the natural level, ??? ???? ???? ?????. Hashem decides the outcome.