On January 23, the Chinese government locked down the city of Wuhan (Hubei Province).  In subsequent days, similar measures were taken in other cities in Hubei and throughout China.  This note offers some preliminary gauge on the effect of the measures taken to protect public health on economic activity in China.   We will make use of three sources of data.  First, there already is some official data on industrial output.  Second, we make use of data on trucking flows to measure the flow of goods across China.  Third, we use data from Baidu to estimate the effect on services and worker movements within China.