Household sims, butlers and maids spend FOREVER vacuuming piles of ashes after a fire, but after the vacuuming animation completes, the pile is still there.
Actually Mary there is dust left behind
The offending piles are:
Related: Sims will also only throw away one of these piles at a time, rather than pick them all up (like they do with trash piles), as mentioned in this report.
