By Francesca Giuliani-Hoffman, CNN

(CNN) -- Tulane University in New Orleans may be among the most famous "party schools" in the country, but students gathering in groups of more than 15 during the pandemic now risk getting suspended or expelled.

"Do not host parties or gatherings with more than 15 people, including the host. If you do, you will face suspension or expulsion from the University," Dean of Students Erica Woodley cautioned -- in bold and all-caps text -- in an email sent to students on Tuesday and posted on Tulane's website.

Gatherings of any size will require social distancing and participants "should wear masks," according to the email.

"There is no room for error here. People's lives depend on your adherence to these rules," Woodley wrote.

The stern warning was sent in reaction to photos and videos posted to social media that showed Tulane students holding large parties over the July Fourth weekend without wearing masks or observing proper social distancing, according to the email.

These actions, in Woodley's words, "were very publicly disrespectful to the Tulane University community and to the people of New Orleans, and have the potential to undermine our significant progress against this deadly disease."

Woodley went on to define the students' behavior as "disrespectful, selfish and dangerous" and "indefensible and truly shameful."

"Do you really want to be the reason that Tulane and New Orleans have to shut down again?," she wrote.

Concerning trends in New Orleans

Gatherings in bars and restaurants are causing concern for leaders in New Orleans, who worry that community spread might bring the city back to Phase One, or to a full shut down.

"Since entering Phase Two, and predominantly since reopening bars in New Orleans a few weeks ago, we have seen an increase in the number of large parties and gatherings taking place," said Sarah Babcock, director of policy and emergency preparedness for the New Orleans Health Department.

"These events have been particularly attended by young people, and that seems to be correlating with large percentages of people age 18 to 29 who are testing positive for Covid-19 in both New Orleans and across Louisiana," Babcock told CNN.

According to Babcock, on July Fourth weekend, the city of New Orleans received 100 large-gathering complaints and 169 business complaints, at least 32 of which involved bars.

On Wednesday, New Orleans Mayor Latoya Cantrell announced new restrictions on restaurants and bars in the city to curb community spread as cases rise. Starting on July 11, indoor seating will be limited to 25 patrons, and bar service will be prohibited.

Tulane students are not the only New Orleans residents congregating in bars or throwing parties. Babcock also mentioned bars in the LSU area and high school graduation parties around town.

"Bourbon street worries me," Mayor Cantrell said in her remarks on Wednesday.

Covid-19 doesn't only affect the elderly

Young residents should be aware that Covid-19 doesn't only affect the elderly, according to Babcock.

"Many young people are getting sick, we are seeing people in their twenties and thirties dying, having strokes, having very severe complications," she said.

People ages 24 and younger are testing positive at higher rates, New Orleans Health Department Director Dr. Jennifer Avegno said on Wednesday, and Babcock said her team is now focusing on analyzing hospitalization data to learn more about the full extent of the problem.

"We are currently looking at our hospitalization rate because the number of young people being hospitalized in New Orleans is starting to increase," she said.

Babcock praised Tulane University's strong stance against parties and large gatherings.

"We are proud to have local universities taking our guidelines seriously and partnering with us to slow the spread of Covid-19 in our community," she said.

"A lot of our students live off-campus in apartments, they are living in the community with other people, and their actions have consequences for our entire community. That includes bartenders and service industry employees that they may be around."

Mayor Cantrell also commended Tulane's leadership approach to the issue: "I'm hoping that other institutions will follow so there will be a unified message," she said.

Looking ahead to the fall

Dean Woodley's message to Tulane's students comes as the university plans to reopen for the fall semester on August 19.

Among the measures announced in May by university president Michael Fitts are frequent testing for people on campus throughout the year, adjustments to the capacity of classrooms and dorms, and an on-campus infirmary to care for students who test positive for the virus.

Woodley emphasized how partying has no place on campus as things reopen.

"The calculation is simple -- If you want to have a residential experience at Tulane in the fall, you have to behave differently," the Dean's email reads.

Students are encouraged to use an online reporting system or call Tulane University Police to hold their peers accountable.

What the students think

Sam Broth, a rising junior at Tulane studying math and computer science, said Woodley's email to the student body was "great."

"Hopefully it shows the surrounding community that not all Tulanians are trying to destroy the progress New Orleans has made as a city," Broth told CNN via Twitter.

Broth is spending the summer back home in the Las Vegas area, but is planning to return to his shared apartment in New Orleans in early August, gearing up for the fall semester on campus.

"Honestly I really am excited to go back. I know that I will be fine doing my best to stop the spread which is the same I've been doing at my house hundreds of miles away. But it is concerning that not only can some students ruin the best college experience possible in these times for us, but they can also hurt the community very badly," Broth added.

Adolfo Garcia, the president of the Undergraduate Student Government at Tulane University, has a similar outlook on the situation.

"I think Dean Woodley's email directly addressed the importance of our students following safety and health protocols. It was a tough email but it drove home the point that we are responsible for the safety of our community members and that there will be consequences," Garcia told CNN via email.

"I've received a lot of messages from students who are concerned about the number of parties happening -- most students haven't returned to campus yet. Tulane is an amazing place, and right now I think most students are hoping we are able to come together in the Fall in the safest way possible," he added.

Doing it for New Orleans

Garcia is a rising senior working toward a double major in finance and legal studies. He lives in New Orleans and is a tour guide on campus.

"What I always like to say is that New Orleans is one of the most unique and celebratory cities in the world. The people, food, and culture are unlike anywhere else, and it shows," he said.

"Surely, there's a lot to miss during the pandemic, but the safety of our city should be everyone's number one priority," he added.

According to Garcia, Tulane has been moving away from its reputation as a "party school," and he advises his fellow students to live by the motto of the university, "non sibi sed suis," or "not for one's self but for one's own."