Here are some precautions which should enable industry to slowly start up. I am not an expert and welcome corrections or additions. As I understand and am reading much of this comes from U of WA health people and what seems to be happening in Naval Base Kitsap.
Sick people should stay home (and this entails generous sick pay)
People should be monitored, say on coming to work, once during the day, and at the end of the day. (this could be self monitoring)
Symptoms monitored: temperature, coughs and sneezes (although I have read the later is not a symptom), and respiratory distress
Redesign work place to eliminate all unnecessary worker contacts, i.e., engineer in 6 foot social distancing whenever possible
Testing (US is still doing very poorly at this), if a person needs testing, they and co-workers need to be put on home leave until negative results come back. Desperate need for ultra fast and fairly accurate testing. It may be coming.
While pre-symptomatic spreading is possible, it may be significantly less than post-symptomatic. This would be a significant distinction.
I live in Kitsap County, and I am impressed with the response here - the state has ramped up without being authoritarian, the US Navy has strict but practical requirements.
My son works on base - his work group must have people on site for work to proceed. Those over 60 or have high risk are required to telecommute, also a lot of telecommute volunteers in his group: 4 now work on site, 8 are telecommuting, he is now the head of the group because his boss is over 60 and is at home. Entry to the bases is on a "as needed" basis, I have badges for the base but I can only go on base for work related things - no social.
I go to the Kaiser Permanente HMO, they require for patients to call in first (well staffed lines) that assess each case, if a clinic visit is needed, the doctor sends a note. Entering the parking lot everyone is guided to a drive thru monitoring tent that checks out the patient, that segregates the contagious from the others and the intake for the clinics are now separated out - all before entering the building. Well done precautions without being overboard.
Home Depot, Target, and Costco are all open, checking people at the entrance along with instructions to social distance, lots of Purel and clorox wipes. Cashiers and workers all wearing disposable gloves. Construction sites are segregating each subcontractor's crew keeping like 20 feet apart those that do not usually work together. At the drive in everyone is wearing disposable gloves, some are wearing masks that want them. A reasonable blend of caution but still keeping the economy going. Traffic on the roads is like 1/4 or less of typical traffic.
Washington was at the forefront with isolation and limiting groups to 10 or less, they kicked in when really all of are cases were around the nursing home that loads of victims came from. The jury is out still but our state seems to be at a plateau, sort of the same numbers of new cases and deaths each day since mid-week, not the sharp increases that New York is seeing.