Lawmakers in Washington are prodding technology companies to take steps to limit the visibility and reduce the risks of a website that provides detailed instructions about suicide and has been linked to a trail of deaths.

Responding to a New York Times investigation of the site published this month, the House Committee on Energy and Commerce on Monday released a bipartisan statement requesting briefings from search engines, web-hosting companies and other tech companies whose services might have been leveraged by the suicide site.

“It is imperative that companies take the threat of such sites seriously and take appropriate steps to mitigate harm,” said the statement from the panel, led by Representative Frank J. Pallone Jr., Democrat of New Jersey.

A representative for Microsoft’s search engine, Bing, told The Times last week that the company had altered its search engine to lower the site’s ranking. On Monday, Senator Richard Blumenthal, Democrat of Connecticut, sent a letter to Google and Bing asking the companies to fully remove the suicide site from their search results — a step further than either search engine was willing to take.

Members of the site are anonymous, but The Times identified 45 people who had spent time on the site and then killed themselves in the United States, the United Kingdom, Italy, Canada and Australia. Most of them were under 30, including several teenagers. The Times also found that more than 500 members of the site wrote so-called goodbye threads announcing how and when they planned to end their lives, and then never posted again.

In recent days, law enforcement officials in Uruguay, where one of the two men who started the site in 2018 lives, began an investigation into the website. The two men resigned as administrators. And the new administrator made the site private, meaning that the content — including discussions about suicide methods, messages of support and thumbs-up emojis to those sharing plans to take their lives, and even real-time posts written by members narrating their attempts — is now visible only to members and not the public.

Families of those who spent time on the website and learned ways to die have long sought accountability from tech companies that lead people to the site, including search engines. The site draws six million page views a month, and nearly half of all traffic is driven by online searches, according to data from Similarweb, a web analytics company,

A representative for Microsoft said that in response to The Times’s investigation, the company had “taken action in line with our policies” and “addressed the ranking associated with this website in our results,” making the site rank lower for most related searches.

Citing The Times’s reporting, Mr. Blumenthal wrote in his letter, addressed to Google’s chief executive, Sundar Pichai, that the content on the suicide site “makes the world a dark place for too many,” and that Google had the ability and legal authority to steer “people who are struggling away from this dangerous website.”

“Google’s hands are not tied, and it has a responsibility to act,” he wrote.

In an email to The Times, Lara Levin, a spokeswoman for Google, declined to comment on the investigation or the senator’s letter.

Mr. Blumenthal made the same case in his letter to Microsoft, writing to the company’s chief executive, Satya Nadella, and its president, Brad Smith. The Microsoft representative declined to make any additional comment.

The operators of the suicide site have long used Cloudflare, an American firm that provides cyberprotections, to obscure the names of its web host, making it difficult or impossible to know what company is providing those services.

In 2019, Cloudflare was notified of the dangers of the suicide website by Australian government officials. The next year, parents whose children had died while participating in the site asked Matthew Prince, Cloudflare’s chief executive, to stop providing its services to the site, but he did not respond. Cloudflare declined to respond to a request for comment for this article.

The two men who started the site, using the online names Marquis and Serge, had tried to hide their true identities. But using domain registration records and invoices, financial documents, other online activity, court records and interviews, The Times revealed that they are Lamarcus Small, 28, of Huntsville, Ala., and Diego Joaquín Galante, 29, of Montevideo, Uruguay.

Mr. Small denied any involvement with the site. Mr. Galante acknowledged in an email that he had posted on the site as Serge, but denied that he was a founder or an operator of it.

After the article was published, on Dec. 9, Marquis announced on the site that he was resigning as an administrator, permanently deleting his account and turning over operation of the site to someone using the online name RainAndSadness.

Mr. Small and Mr. Galante also resigned as administrators of several websites they operated for involuntary celibates, or incels, men who believe women will never have sex with them because of their looks and social status.

In Uruguay, where assisting suicide is a crime, the Montevideo police have begun an inquiry in collaboration with a local prosecutor’s office in response to The Times’s investigation, said Javier Benech, a communications director for the office.

In the United States, while many states have laws against assisting suicide, they are often vague, do not explicitly address online activity and are rarely enforced.

Members of the suicide site who post instructions on how to die by suicide, or encouragement to follow through with it, could be vulnerable to criminal charges depending on the jurisdiction. But so far, no American law enforcement officials have pursued such cases in connection with the website. Federal law typically protects website operators from liability for users’ posts.