The U.S. Department of Transportation will allow airlines to cut more of their flights after passenger counts hit record lows because of the coronavirus pandemic.

Originally, the DOT had required each airline to continue flying to every point on its U.S. route map as a condition of accepting billions in federal stimulus funding.

However, airlines have seen passenger counts drop more than 90% amid the COVID-19 outbreak, so they asked for exemptions. There were other factors as well.

For about a week in late April, Delta was unable to operate most of its flights at the Albany, N.Y. airport after one employee fell ill and most of the other employees were told to self-quarantine, the airline said in a Tuesday filing. The sick employee ended up testing negative for COVID-19.

The airlines "contend that services to certain points in their networks are unreasonable, impracticable, costly, and challenging to complete in light of public health and safety concerns," the DOT said in a notice Tuesday

It said it will exempt airlines from flying to 5% of their route networks. That means the carriers would still need to continue flying to 95% of the places they served before the pandemic hit.

The DOT said it aims to reduce airlines’ financial burden and provide flexibility, while allowing places across the country to maintain service from at least one carrier. The agency said it will grant exemptions based on airlines’ prioritized lists to prevent any point from losing all airline service.

Delta Air Lines, which accepted $5.4 billion in federal relief funding, previously asked for a waiver to allow it to keep flights to the U.S. Virgin Islands on hold because of restrictions prohibiting tourists. But the DOT did not grant the exemption, so Delta restarted the service. Leisure travelers in the U.S. Virgin Islands are restricted until at least June 1.

Atlanta-based Delta also asked for permission to suspend service to Brunswick, Ga.; Hilton Head, S.C.; Melbourne, Fla. and other small airports around the country. It said on some flights, it was carrying only one passenger per day.

Delta is also halting service at 10 secondary airports across the country, saying that's permitted under DOT requirements because it continues to serve larger airports nearby.