A number of tales exist in folklore of moments in which people have noticed clocks mysteriously stopping around the time that a loved one has died. Seemingly real-life accounts of these apparent "death coincidences" have occasionally turned up in case collections of spontaneous psychic experiences, including the extensive collection compiled by the late Louisa Rhine. [1,2] An illustrative example case comes from a young girl in New England, which appeared in Chapter 14 of Rhine's classic 1961 book Hidden Channels of the Mind:
I never could explain this. When my father died, the clock was found to have stopped just at the same time. Later when I took it to the jeweler, because it would not run, he said it was beyond repair. It was a Swiss clock and had been a wedding gift to my parents; Dad had always kept it going, but we never got it to run again. [3, p. 214]
It seems that cases like these are still occasionally reported in more recent times, as indicated by a survey study conducted by British psychiatrist Peter Fenwick and his colleagues , which found that around one-third of the nurses, doctors, and caregivers they had interviewed at two hospices and a nursing home reported similar incidents with clocks (and other objects). Among them were the two following accounts:
"One person told me her watch had stopped at the moment her husband died and she never got it repaired. I saw her six months later at the service and I said to her: 'Have you still got the watch?' and she laughed; she said, 'Yes, I bought a new one. I'm not going to have it repaired. It hasn't gone [i.e., worked] since."
"A friend of mine, her twin sister died and they were just so close, I'm sure she could have told you far more but I do remember about the clock stopping at the time of Maggie's death. This was the surviving sister, in her house, and they were living separately but only just around the corner from each other." [4, p. 176]
For cases like the ones above, involving a single clock, one might figure that the stopping was simply due to the clock having broken down (perhaps from age or defective workings), its battery power having run out, or it having not been properly wound up. But another example case from Rhine's collection, which is particularly notable for the number of clocks involved, had reportedly taken place during the Thanksgiving holiday, according to the woman in Florida who reported it:
We had a pendulum clock (which we wound every Sunday) in our room. We also had a musical clock which we wound every evening, and we had my husband's pocket watch. On the evening before Thanksgiving day, 1913, we talked a minute and said good night to each other. All three clocks stopped at once.
My husband got up, gave the weights a shove, shook the little musical clock and his pocket watch; and they ran again.
In two weeks we received word that my husband's father in Austria had died the same day and hour. [1, pp. 109 - 110]
If this event had indeed taken place just as the woman recounted it, and the three clocks in this case hadn't simply wound down at the exact same moment purely by chance, then the coincidence of three separate clocks stopping at roughly the same time would seem to be rather intriguing. As notable as it is, though, one must keep in mind that a case like this cannot really be taken as evidential, since it isn't possible for one to assess (from the account alone) any other conventional factors which might've subtly played a role in the stopping of the clocks.
There may, however, be a bit of leeway for considering the possible involvement of a parapsychological factor in cases like these when one takes into account the number of other cases like them that have been reported. In surveying her collection, Louisa Rhine found 95 reports of anomalous physical effects that reportedly occurred around the time of someone's death, 39% of which involved clocks that seemed to suddenly stop at the time of death.  The remainder consisted of other kinds of seemingly mysterious physical effects such as pictures and other objects falling from a wall, mantle, or shelf; objects seeming to suddenly break or explode, doors seeming to open or close of their own accord, and lights turning on or off with no one touching them. A later survey made by parapsychologist Carlos Alvarado  of cases collected by the French astronomer Camille Flammarion, as well as researchers in Italy, had found similar effects being reported, as shown in the following table.
Ostensibly Anomalous Physical Effects Reported Around the Time of Death
Table based on data compiled and reported by Alvarado 
As Rhine had observed, these physical effects are often witnessed by a close relative or friend of the person that died, and they are traditionally taken as being "signs" or "messages" of that person's death (which the dying person is presumed to have caused through a form of psychokinesis - PK, or "mind over matter"). While that might be one possibility, Rhine pointed out that one should also consider the alternate possibility that the relative or friend who witnessed the occurrence could've brought it about themselves through PK, as well, perhaps as a kind of unconscious psychic "reaction" of sorts to the dying person's crisis situation.  This alternate possibility might seem plausible based on several factors:
There are various experimental tests of PK that have been conducted over the past eight decades which have produced results to suggest that the human mind may be capable of subtly affecting physical objects such as rolling dice or the number sequences being produced by electronic random number generators (RNGs) to degrees significantly beyond pure chance alone. [5-10; for general overviews, see 11-13]
As Rhine pointed out, similar kinds of anomalous physical effects have also been reported in cases where there was no apparent "death coincidence" involved. 
The idea that the effect might be triggered by PK on the part of the relative or friend who witnessed it (perhaps as a psychic "reaction" to the dying person's crisis) might initially seem plausible based on the observation made by the late William Roll  that in several of the cases in Rhine's collection, the witnesses seemed to feel brief surges of emotion or unusual feelings that apparently came on quite suddenly, either during or just before the physical effect took place. For instance, one witness said that at the time a book seemed to mysterious fall from a shelf, "I don't when my mind has ever been so stirred and perhaps that is why it [i.e., the book falling] happened" [1, p. 96]. Another witness stated that just before a picture fell from the wall, he "...felt a surge of blood racing through my veins" [1, p. 99]. A third witness reported experiencing "the queerest feeling, and a chill passed over my body," while a fourth reported that she began to cry all of a sudden, for no clear reason [1, p. 112]. Roll pointed out that this is very similar to the situation found in cases of recurrent spontaneous psychokinesis (RSPK, or "poltergeist" phenomena), where the suspected poltergeist agent may often be in a state of emotional tension, usually in response to the unsettled psychological situation that the agent finds him or herself in [15-16]. There is also some preliminary empirical evidence to suggest that there may be a correlation between emotional expression and PK, as well. [17-19]
This alternate possibility would suggest that the friend or relative who witnessed the clock stopping might not be just a passive observer - rather, they might actually play a more active role in "death coincidences" than one might initially think. Thus, the question of "who's doing it?" may not be so straightforward in this case.
One should recognize that the same kind of situation arises when considering objects that seem to mysteriously move on occasion in haunting cases - who's doing it: a ghost, or a living person? This is one of the things which currently makes it hard to build a strong case for spirit existence, but perhaps with additional research findings, this question - which remains open for the moment - can be more fully addressed and resolved.
The PRF would like to wish everyone a pleasant Thanksgiving holiday!
 Rhine, L. E. (1963). Spontaneous physical effects and the psi process. Journal of Parapsychology, 27, 84 - 122.
 Alvarado, C. S. (2006). Neglected near-death phenomena. Journal of Near-Death Studies, 24, 131 - 151.
 Rhine, L. E. (1961). Hidden Channels of the Mind. New York: William Morrow & Company, Inc.
 Fenwick, P., Lovelace, H., & Brayne, S. (2010). Comfort for the dying: Five year retrospective and one year prospective studies of end of life experiences. Archives of Gerontology and Geriatrics, 51, 173 - 179.
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 Radin, D. I., & Nelson, R. D. (2003). A meta-analysis of mind-matter interaction experiments from 1959 to 2000. In W. B. Jonas & C. C. Crawford (Eds.) Healing, Intention, and Energy Medicine: Science, Research Methods and Clinical Implications (pp. 39 – 48). Edinburgh, UK: Churchill Livingstone.
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 Jahn, R. G., Dunne, B. J., Nelson, R. D., Dobyns, Y. H., & Bradish, G. J. (1997). Correlations of random binary sequences with pre-stated operator intention: A review of a 12-year program. Journal of Scientific Exploration, 11, 345 - 367.
 Dobyns, Y. H. (2015). The PEAR Laboratory: Explorations and observations. In D. Broderick & B. Goertzel (Eds.) Evidence for Psi: Thirteen Empirical Research Reports (pp. 213 - 236). Jefferson, NC: McFarland & Company, Inc.
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 Roll, W. G. (1983). Recurrent and nonrecurrent psi effects. Journal of Parapsychology, 47, 341 - 346.
 Roll, W. G. (1972/2004). The Poltergeist. Garden City, NY: Nelson Doubleday, Inc. (Reprinted by Paraview Special Editions)
 Rogo, D. S. (1986). On the Track of the Poltergeist. Englewood Cliffs, NJ: Prentice Hall.
 Blasband, R. A. (2000). The ordering of random events by emotional expression. Journal of Scientific Exploration, 14, 195 - 216.
 Lumsden-Cook, J. (2005). Mind-matter and emotion. Journal of the Society for Psychical Research, 69, 1 - 17.
 Lumsden-Cook, J. (2005). Affect and random events: Examining the effects of induced emotion upon mind-matter interactions. Journal of the Society for Psychical Research, 69, 128 - 142.