Oahu reported 180 new cases of COVID-19 on Sunday, and Honolulu Mayor Kirk Caldwell warned that the island could revert to the more-restrictive Tier 1 activity and business limits if the trend continues.

“We keep this number over the next two weeks, we’ll be snapping back to Tier 1 in the beginning of the new year, meaning gyms are shut down, restaurant go to just five family members,” Caldwell said Sunday at a noon news conference.

“The opening and shutting of our island is hugely damaging. It does bring down the cases. It worked twice and brought down the cases dramatically,” Caldwell said. “But there’s a lot of bloodletting with businesses. And every time you do it — this is the second time, I don’t want to do it a third time — the blood drains even quickly, and it’s harder for them to recover.”

If Oahu has more than 100 new daily cases on average for two consecutive weeks, the county will move to Tier 1 from the current Tier 2. Oahu’s seven-day average on Sunday was 113.

Caldwell said many of the new cases on Oahu are from the Halawa Correctional Facility. He said he is urgently petitioning Gov. David Ige to allow him to remove inmate coronavirus counts from the island’s reopening metrics.

Caldwell said he has been told unofficially by the state Department of Health that as many as 93 of the Oahu cases reported Sunday may have come from the Halawa prison.

Statewide health officials Sunday reported 204 new infections and one new death, bringing the totals since the start of the pandemic to 282 deaths and 20,217 cases.

“The number of cases on Oahu alone was 180,” Caldwell said. “We haven’t seen this number of cases since Sept. 5 — that was the last time we saw a spike and we had to shut down Oahu. We’re seeing a similar pattern.”

Caldwell said he first asked Ige to remove the inmate coronavirus count from Oahu’s reopening metrics a week and a half ago. As of Sunday evening Caldwell’s team still didn’t have an answer.

Lt. Gov. Josh Green told the Honolulu Star-Advertiser on Sunday, “If the mayor discusses with the governor whether or not to count those (cases) toward his tiers, that’s his prerogative because the cases that occur in the prison are not increasing our risk of widespread disease.”

“It would be OK for him to pull (prison cases) out, but the Department of Health and I will continue to gauge whether or not it’s having an impact on our overall health capacity,” Green said.

Green said prison cases don’t expose society to increased spread, but can affect health care.

“We have seen an uptick of prisoners being transferred to the hospital. We’re gone from 58 to 68 in the hospital, and many of those are from the prison population,” he said. “We’ve seen a small increase in our hospital number, although it’s still very good compared to our peak at 300-plus.”

Caldwell said his request, if approved, would apply only to inmates and not workers at the correctional facilities, who spend time in the community.

So far, Caldwell said, the rise in inmate cases has not strained Oahu’s ability to meet its health care needs. If health care strain occurred, Caldwell said he expects the county could quickly adjust its reopening metrics.

Caldwell also made a plea to Oahu residents to stay vigilant about mask-wearing, hand-washing and social-distancing because “the virus travels quickly if we let our guard down.”

The U.S. coronavirus death toll was more than 316,000 Sunday.

Oahu is by far the island most affected by coronavirus health harms. The numbers of coronavirus cases by island since the start of the outbreak are 17,054 on Oahu, 1,803 in Hawaii County, 771 on Maui, 137 on Kauai, 106 on Lanai and 22 on Molokai. There are also 324 Hawaii residents diagnosed outside of the state.

The official state Department of Health coronavirus-related death toll includes 218 fatalities on Oahu, 44 on Hawaii island, 17 on Maui, one on Kauai and two Hawaii residents who died on the mainland.

Sunday’s new statewide infection cases reported by the Health Department also included 13 cases on the Big Island and 11 on Maui. The statistics released Sunday reflect the new cases reported to the department through 11:59 p.m. Friday.

The Kauai District Health Office reported one new case of COVID-19 on Sunday that wasn’t included in the Health Department’s count. Kauai officials said the source of the infection is under investigation, but the case involved an adult female visitor.

Kauai had little community spread before the state launched Safe Travels Hawaii, a pre-arrival testing program. Ige allowed Kauai to opt out of Safe Travels on Dec. 2. Currently, all mainland and interisland passengers arriving on Kauai are under a mandatory 10-day quarantine.

Hawaii health officials said that of the state’s total infection count, 1,632 cases are considered to be active. The number of active cases in the state rose by 103 Sunday.

With the holidays approaching as COVID-19 cases surge across the county, the Hawaii Emergency Management Agency is strongly urging residents to avoid gatherings of five or more people and to continue other practices aimed at reducing coronavirus spread.

“I challenge you all to find safer ways to celebrate this holiday season,” said HI-EMA Administrator Luke Meyers. “Spread love and joy, not COVID.”