1989 Loma Prieta earthquake significant issue, especially in the heavily damaged Marina District of San Francisco, but its effects were also seen in the East Bay, and near the shore of Monterey Bay, where a non-destructive tsunami was also observed. Due to the sports coverage of the 1989 World Series, it became the first major earthquake in the United States that was broadcast live on national television (and is sometimes referred to as the "World Series earthquake" as a result). Rush-hour traffic on the Bay Area freeways was lighter than normal because the game was about to begin, and this may have prevented a
Earthquake prediction of having observed such phenomena prior to an earthquake, no such phenomena has been shown to be an actual precursor. A 2011 review found the "most convincing" electromagnetic precursors to be ULF magnetic anomalies, such as the Corralitos event (discussed below) recorded before the 1989 Loma Prieta earthquake. However, it is now believed that observation was a system malfunction. Study of the closely monitored 2004 Parkfield earthquake found no evidence of precursory electromagnetic signals of any type; further study showed that earthquakes with magnitudes less than 5 do not produce significant transient signals. The "International Commission on Earthquake Forecasting for