Almost 30 students who recently traveled to Mexico for spring break have tested positive for COVID-19.

Health officials in Austin, Texas, on Tuesday announced an investigation into a "cluster" of COVID-19 cases among a group of roughly 70 people in their 20s who traveled in a chartered plane to Cabo San Lucas, Mexico for spring break about a week-and-a-half ago amid the coronavirus crisis.

"Currently, 28 young adults on this trip have tested positive for COVID-19 and dozens more are under public health investigation," the Austin Public Health Department said. "Four of the confirmed cases did not present any symptoms."

The 28 people who tested positive are currently self-isolating, and more are being monitored while quarantined, according to the statement. The University of Texas at Austin told NBC News that the 28 young adults with COVID-19 are students at the school. Some individuals who went on the trip came back home on commercial flights, according to the Austin Public Health Department's statement.

Austin officials said that although Mexico wasn't under a federal travel advisory when the young adults traveled there, "Austin-Travis County residents should follow CDC's travel recommendations indicating travelers avoid all non-essential international travel," and "a leisure vacation of any kind is not considered essential." The University of Texas at Austin told NBC that this serves as a "reminder of the vital importance" of following health officials' warnings amid the coronavirus pandemic. Brendan Morrow

Democrats in the Pennsylvania state House learned from a reporter on Wednesday that at least one of their Republican colleagues had tested positive for COVID-19 a week earlier. State Rep. Andrew Lewis (R) stepped forward.

Lewis said he had "immediately" informed House leadership of his positive test on May 20, but kept quiet "out of respect for my family, and those who I may have exposed." Rep. Russ Diamond (R) and Rep. Frank Ryan (R) subsequently said they were self-quarantining after coming in contact with an infected person.

House Democrats accused Republicans of covering up the infections to bolster their claims that COVID-19 isn't a significant risk. "It is simply unacceptable that some House Republicans knew about this for more than a week and sat on that knowledge," House Democratic Leader Frank Dermody said Wednesday, adding that "a vocal few" of his GOP colleagues "have attempted to make a virtue out of not wearing a mask when in close proximity to others."

"I have never been this livid: The Republican leadership risked the lives of our staff" and "other members," said Rep. Malcolm Kenyatta (D). Rep. Brian Sims (D) expressed his ire at GOP colleagues in a series of short videos, most of which contain NSFW language.

Mike Straub, a spokesman for House Majority Leader Bryan Cutler (R), said "the health and privacy of a member" is "protected by HIPAA law — so the only person who was at liberty to announce their positive test is the member." He insisted that House Republicans "followed the data and science" and "notified and quarantined" anyone who met guidelines from the CDC and state health department. Democrats noted pointedly that none of them had been contacted.

"Some of our colleagues sat in close proximity to this member during committee meetings," tweeted Rep. Leanne Krueger (D). "The Republican contact tracing program ignored them." Peter Weber

China's National People's Congress approved a controversial bill Thursday that, once enacted, will allow Beijing to exert its power more overtly in semi-autonomous Hong Kong. The 2,878-to-1 vote was expected and it moves the legislation, handed down from China's central government, back to the Standing Committee of the Communist Party. Once the committee finishes writing the law, it could be in force by August or September.

The legislation criminalizes secession, subversion, terrorism, and foreign interference in Hong Kong, and it says that "when needed, relevant national security organs of the Central People's Government will set up agencies in Hong Kong to fulfill relevant duties to safeguard national security in accordance with the law." That has been interpreted as allowing Beijing to set up its own security agencies in Hong Kong, adding a parallel police force. Hong Kong pro-democracy protests have resumed in response.

The new law, and another proposed bill that would outlaw disrespect for China's national anthem in Hong Kong, have fueled concerns about the future of the city as an international financial hub. U.S. Secretary of State Mike Pompeo said Wednesday that the Trump administration no long considers Hong Kong autonomous and may revoke its special trade status. Peter Weber

The U.S. passed 100,000 recorded COVID-19 deaths on Wednesday, by far the highest official death toll in the world. "It's a striking reminder of how dangerous this virus can be," said Kaiser Family Foundation health policy expert Josh Michaud. "The experience of other countries shows that death at that scale was preventable."

President Trump did not mark the sad milestone, tweeting instead the number of tests the U.S. has conducted with the exhortation: "Open safely!" His presumptive Democratic opponent, former Vice President Joe Biden, gave a eulogy for the 100,000 dead and attempted words of comfort for their loved ones. And The Daily Show just compiled a super-reel of Trump, his media allies, and members of his administration praising the Trump administration's response, with patriotic music playing in the background. There is, perhaps appropriately, no punch line at the end. Peter Weber

A protest outside the Minneapolis 3rd Precinct police station tipped into violence for a second night on Wednesday as demonstrators demanded justice in the police killing of George Floyd, a 46-year-old black man, on Monday night. Looting was seen at a nearby Target, Dollar Tree, Cub Foods, and AutoZone, and as night fell, fires broke out in the street and the auto parts store, The Associated Press reports. Police, who fired tear gas and stun grenades Tuesday night, stood guard outside the station but did not appear to intervene to stop the looting.

Police did apprehend a suspect after finding a man shot dead on a sidewalk near the protests. Police spokesman John Elder said the shooting was being investigated as a homicide and the events that led up the death are "still being sorted out." Police Chief Medaria Arradondo urged calm as evening fell, noting that Floyd's death is under several investigations, including one by the FBI. "Justice historically has never come to fruition through some of the acts we're seeing tonight, whether it's the looting, the damage to property, or other things," he said on KMSP-TV.

Minneapolis Mayor Jacob Frey called for the arrest of the white officer who kneeled on Floyd's neck for eight minutes, even as Floyd repeatedly said he couldn't breathe. That officer and three others involved were fired Tuesday. There were also nonviolent protests outside the officer's house and the home of the Hennepin County prosecutor who will decide whether to file charges in the case. Surveillance footage appears to show Floyd cooperating with police, CNN reports, though the public has not yet seen the officer's body-camera.

Police forces around the country have enacted polices in recent years to limit excessive use of force, especially against black and brown people, and Chattanooga Police Chief David Roddy said as far as he's concerned, the video of Floyd's final moments speaks for itself. Peter Weber

"It seems like every day we're learning something new while we're in quarantine," Jimmy Kimmel said on Wednesday's Kimmel Live. For instance, "did you know Hitler had an alligator? Well, he did, and now that alligator is dead."

"The president and his space poodle were in Florida today for the big NASA/SpaceX launch — this would have been the first time ever that a private company sent astronauts into orbit, which would have been a big deal," Kimmel said. "Unfortunately, the mission had to be scrubbed at the last minute due to weather. ... People online are blaming the president for jinxing this thing because he showed up to see it, just like they say he jinxed Alabama by showing up their home game, or how he's jinxed everything he's ever touched, but this is not his fault."

"It's been an all-caps kind of week for our dear mis-leader — Twitter yesterday, for the first time ever, flagged his tweets as potentially misleading," Kimmel said. "I guess this is good, but I don't know. Do we really need Twitter to tell us our fake president tweets fake things? Is that their job? The president, of course, was displeased. He took to Twitter to lash out at Twitter." He read Trump's tweetrum and said he wasn't sure what it meant.

"I guess it was only a matter of time before Donald Trump would be in a Twitter feud with Twitter," Kimmel said. "But this new kick he's on, trying to stop voting-by-mail, is actually very scary, because it's pretty clear he's setting the stage to claim he was cheated if he loses the election, which could potentially result in real violence in this country. And to help him push our democracy toward the edge of a cliff, Kellyanne Conway spoke to reporters today to say: pandemic, schmandemic, real American voters wait in line." At least for cupcakes.

Late Night's Seth Meyers presented a cartoon mashup of Trump's family quarantine and The Shining, and you can watch that below. Peter Weber

Scientists were able to capture rare audio of narwhal vocalizations as several swam through a fjord in Greenland, and they discovered that these elusive whales make some familiar sounds underwater.

Known as the unicorns of the sea, narwhals live in the Arctic waters. Evgeny Podolskiy of Japan's Hokkaido University, who studies the sounds of glaciers, realized that to get a fuller picture, he needed to understand what noises the narwhal makes. Last summer, he led a team of geophysicists to Greenland, where they worked with Inuit hunters to record the different noises of the narwhal. Their study was published Tuesday in the AGU's Journal of Geophysical Research: Oceans.

The team was able to capture narwhals whistling, clicking, and buzzing. Narwhals use echolocation to find food, and the researchers found that the closer a narwhal gets to its prey, the faster it clicks, and the buzzing noise sounds like a chainsaw. When narwhals want to communicate with each other, they whistle. The researchers said the recordings have helped them better understand narwhal behavior and how they find food in the summer. Catherine Garcia