Quake sleuth 'saves' 300,000 lives.

Residents of Calcutta should sleep easier, thanks to seismologist Roger Bilham, who is rewriting the history of their city. Contrary to what most quake scientists learn in school, Bilham reports, Calcutta did not suffer a devastating tremor in 1737 that killed 300,000 people. In seismic listings, this shock often appears among the five deadliest.

A researcher at the University of Colorado at Boulder, Bilham has compiled a string of facts suggesting that the quake either never occurred or killed far fewer people. It supposedly struck on Oct. 11, the same night a strong storm pummelled Calcutta with heavy rain, gale-force winds, and flood waters. When Bilham checked the records of British residents in Calcutta at that time - including those of Oliver Cromwell's grandson - he found many references to the storm but no mention of the quake. The British East India Company reported 3,000 deaths that night in Calcutta and two dozen damaged colonial structures close to the river, where the flooding would have been most severe.

Because he could find no eyewitness accounts of a quake that night, Bilham attributes those deaths to the storm. He notes that records from the city of Dacca, 150 kilometers away, make no note of any earthquake that night.

The earliest reference to the quake that Bilham found appeared in reports by British merchants 6 months after the supposed disaster. A century later, a British seismologist included it in a catalog of Indian earthquakes, and from there it filtered into the seismological literature. Bilham finds the 300000 deaths improbable, in part because the population of Calcutta at the time numbered less than 20,000.

Whether the quake occurred or not has important implications for the 10 million residents of modern Calcutta, Bilham says. The city has no record of other major quakes, and the population is expected to swell another 50 percent in the next decade.