  During the unfolding of a crisis, it is crucial to determine its severity,
yet access to reliable data is challenging. We investigate the relation between
geolocated Tweet Intensity of initial COVID-19 related tweet at the beginning
of the pandemic across Italian, Spanish and USA regions and mortality in the
region a month later. We find significant proportionality between early social
media reaction and the cumulative number of COVID-19 deaths almost a month
later. Our findings suggest that "the crowds" perceived the risk correctly.
This is one of the few examples where the "wisdom of crowds" can be quantified
and applied in practice. This can be used to create real-time alert systems
that could be of help for crisis-management and intervention, especially in
developing countries. Such systems could contribute to inform fast-response
policy making at early stages of a crisis.
