SAN FRANCISCO — It was just after 11 a.m. last Wednesday when Jaime Maldonado, 51, pulled his rented Nissan into a lot outside San Francisco International Airport. He figured he had a long wait ahead — about two hours — before Lyft would ping him to pick up a passenger.

Occasionally, jets roared overhead — but not many, which meant not enough passengers for Mr. Maldonado, who said that before the coronavirus outbreak, he spent just 20 to 40 minutes waiting outside the airport for customers. To kill time, he got out of his car, looping the mask he recently started wearing around his wrist, and went to talk to other drivers.

As the minutes ticked by, Mr. Maldonado wondered out loud, “What am I going to do to pump gas and feed my kids tomorrow?” His number of rides in a typical week had dropped to around 50 from 100 earlier in the month, he said, and his payout had plunged by half to about $600 a week, from which Lyft would subtract the rental fee for his car.

The coronavirus pandemic is exposing the fragile situations of gig economy workers — the Uber and Lyft drivers, food-delivery couriers and TaskRabbit furniture builders who are behind the convenience-as-a-service apps that are now part of everyday life. Classified as freelancers and not full-time employees, these workers have few protections like guaranteed wages, sick pay and health care, which are benefits that are critical in a crisis.