5. Major cities are turning to an A.I. start-up to help save lives during natural disasters. But some fear its promise has been dangerously exaggerated.

A Times investigation found that One Concern inflated its tools’ abilities and kept outside experts from reviewing its methodology. Now, San Francisco, an early adopter of One Concern, is ending its contract with the service, in part because of concerns about whether its predictions are trustworthy. Above, three versions of a One Concern product gave very different damage predictions for the same hypothetical 7.0-magnitude Seattle-area earthquake.

Separately, a revised prediction from federal forecasters sees the potential for as many as 17 named storms this hurricane season, four of which may be major. The new analysis suggests that an above-average season is substantially more likely than the agency first predicted in May.

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