Republican Senator for Michigan, William Alden Smith, had previously investigated railroad safety issues. When he heard news of the Titanic disaster, he saw an opportunity to establish an investigation. Carpathia was still on her way to New York, and Senator Smith knew he had to move quickly while they still vividly remembered the sinking and before they scattered across America or returned to England.

He attempted to contact US President, William Howard Taft, but was told by the president’s secretary that no action was intended. Regardless, Smith took his own initiative and on April 17, 1912, two days before Carpathia arrived in New York, Smith proposed a resolution in Senate that would grand the Committee on Commerce powers to establish a hearing to investigate the sinking.

The resolution passed and Senator Knute Nelson, chair of the Commerce Committee, appointed Smith as chair of a sub-committee to carry out the hearings. Senator Smith subsequently met President Taft and they arranged the details of the inquiry, including a naval escort for Carpathia to ensure no one left the ship before it docked.

Senator Smith, and fellow senator and subcommittee member Francis G. Newlands as well as other officials travelled by train to New York, in time to meet the Carparthia as it docked on the evening of 18 April, 1912.

Smith and his colleagues boarded the Carpathia and served subpoenas to J. Bruce Ismay, chairman and managing director of the White Star Line, as well as other surviving officers. They were required to remain in the United States and give testimony at the inquiry.

The hearings began on the morning of 19 April, 1912, in the Waldorf Astoria Hotel in New York City. They later moved to the Russell Senate Office Building in Washington D.C. Seven senators served on the subcommittee, with three Republicans and three Democrats in addition to Smith as chair. The other six senators were Jonathan Bourne (Republican, Oregon), Theodore E. Burton (Republican, Ohio), Duncan U. Fletcher (Democrat, Florida), Francis G. Newlands (Democrat, Nevada), George Clement Perkins (Republican, California), and Furnifold McLendel Simmons (Democrat, North Carolina). The composition of the subcommittee was carefully chosen to represent the conservative, moderate and liberal wings of the two parties.

Questioning was carried out by various members of the committee at different times, rather than all seven senators being present at all times. However, the work of the committee was very much dominated by Smith, who personally conducted the questioning of all of the key witnesses. This caused some tension among the members of the committee and made him a number of enemies, as it was interpreted as an attempt to seize the limelight. It resulted in some members of the committee only attending the hearings infrequently as there was little for them to do.

Surviving officials, crew and passengers who were questioned or provided evidence included J. Bruce Ismay, Charles Lightoller (Second Officer on Titanic); the lookout who sounded the alarm, Frederick Fleet; the surviving wireless operator, Harold Bride; and first-class passenger Archibald Gracie. Those that testified from among the captains and crew of other ships included Arthur Rostron (Captain of Carpathia), Harold Cottam (wireless operator on Carpathia), Stanley Lord (Captain of SS Californian), and Herbert Haddock (Captain of RMS Olympic). Expert witnesses, speaking or corresponding on subjects such as radio communications, iceberg formation, and newspaper reporting, included Guglielmo Marconi (Chairman of the Marconi Company), George Otis Smith (Director of the United States Geological Survey), and Melville Elijah Stone (General Manager of the Associated Press).

Others called to give testimony included Phillip A. S. Franklin, Vice President of International Mercantile Marine Co., the shipping consortium headed by J. P. Morgan that controlled White Star Line.

In his quest for the truth about the sinking of the RMS Titanic, Senator William Alden Smith vigorously fought against the steamship companies, conservative newspapers, and the British Board of Trade. Some of the Titanic’s surviving officers, especially Second Officer Charles Lightoller, never forgave Senator Smith for exposing their responsibility in the Titanic’s accident.

With his persistent, low key style of cross examining the witnesses, Senator Smith often repeated the same questions over and over to wear down a hostile witness.

The inquiry concluded with Smith visiting Titanic's sister ship Olympic in port in New York on 25 May 1912, where he interviewed some members of the crew and inspected the ship's system of watertight doors and bulkheads, which was identical to that of Titanic. The subcommittee issued a final report on May 28. It was nineteen pages long, with 44 pages of exhibits and summarized 1,145 pages of testimony and affidavits. Some notable findings included:
A lack of emergency preparations had left Titanic's passengers and crew in "a state of absolute unpreparedness", and the evacuation had been chaotic: "No general alarm was given, no ship's officers formally assembled, no orderly routine was attempted or organized system of safety begun."
The ship's safety and life-saving equipment had not been properly tested.
Titanic's Captain, Edward Smith, had shown an "indifference to danger [that] was one of the direct and contributing causes of this unnecessary tragedy."
The lack of lifeboats was the fault of the British Board of Trade, "to whose laxity of regulation and hasty inspection the world is largely indebted for this awful tragedy."
The SS Californian had been "much nearer [to Titanic] than the captain is willing to admit" and the British Government should take "drastic action" against him for his actions.
J. Bruce Ismay had not ordered Captain Smith to put on extra speed, but Ismay's presence on board may have contributed to the captain's decision to do so.
Third-class passengers had not been prevented from reaching the lifeboats, but had in many cases not realised until it was too late that the ship was sinking.

The report was strongly critical of established seafaring practices and the roles that Titanic's builders, owners, officers and crew had played in contributing to the disaster. It highlighted the arrogance and complacency that had been prevalent aboard the ship and more generally in the shipping industry and the British Board of Trade. However, it did not find IMM or the White Star Line negligent under existing maritime laws, as they had merely followed standard practice, and the disaster could thus only be categorised as an "act of God".

Senator Smith made a number of recommendations for new regulations to be imposed on passenger vessels wishing to use American ports, namely,
Ships should slow down on entering areas known to have drifting ice and should post extra lookouts.
Navigational messages should be brought promptly to the bridge and disseminated as required.
There should be enough lifeboats for all on board.
All ships equipped with wireless sets should maintain communications at all times of the day and night.
New regulations were needed to govern the use of radiotelegraphy.
Adequate boat drills were to be carried out for passengers.
Rockets should only be fired by ships at sea as distress signals, and not for any other purposes.

The inquiry was heavily criticised in Britain. Even though Titanic was (indirectly) owned by an American consortium, the International Mercantile Marine, the inquiry was seen as an attack on the British shipping industry and an affront to British honor. The subcommittee was criticized for having the audacity to subpoena British subjects while Smith himself was ridiculed for his apparent naiveté.

Many newspapers published scathing editorial cartoons depicting Smith in unflattering terms. The Morning Post asserted that "a schoolboy would blush at Mr. Smith's ignorance" while the Daily Mirror denounced him for having "made himself ridiculous in the eyes of British seamen. British seamen know something about ships. Senator Smith does not." The Daily Telegraph suggested that the inquiry was fatally flawed by employing non-experts, which had "effectively illustrated the inability of the lay mind to grasp the problem of marine navigation." Similar concerns were expressed by the Daily Mail, which complained that "it has no technical knowledge, and its proceedings ... show a want of familiarity with nautical matters and with the sea", and by the Evening Standard, which criticized the inquiry for being "as expert in investigating marine matters as a country magistrate's bench might have been." The Daily Express called him "a backwoodsman from Michigan", which the newspaper characterized as a state "populated by kangaroos and by cowboys with an intimate acquaintance of prairie schooners as the only kind of boat". His closing speech to the Senate came in for particularly harsh criticism from the British press, which termed it "bombastic", "grotesque" and "a violent, unreasoning diatribe."

The British government was also hostile towards the inquiry. Sir Edward Grey, the Foreign Secretary, spoke of his contempt for the way the senator had put the blame in a "denunciatory" fashion on the inadequate regulations implemented by the British Board of Trade. The British Ambassador to the United States, James Bryce, demanded that President Taft should dissolve the committee and refused to recognise its jurisdiction.

Some British writers, however, applauded the inquiry. G. K. Chesterton contrasted the American objective of maximum openness with what he called Britain's "national evil", which he described as being to "hush everything up; it is to damp everything down; it is to leave the great affair unfinished, to leave every enormous question unanswered." He argued that "it does not much matter whether Senator Smith knows the facts; what matters is whether he is really trying to find them out." The Review of Reviews, whose founder William Stead was among the victims of the disaster, declared: "We prefer the ignorance of Senator Smith to the knowledge of Mr. Ismay. Experts have told us the Titanic was unsinkable – we prefer ignorance to such knowledge!"

The American reaction was also generally positive. The New York Herald published a supportive editorial commenting: "'Nothing has been more sympathetic, more gentle in its highest sense than the conduct of the inquiry by the Senate committee, and yet self-complacent moguls in England call this impertinent ... This country intends to find out why so many American lives were wasted by the incompetency of British seamen, and why women and children were sent to their deaths while so many British crew have been saved." The American press welcomed Smith's findings and accepted his recommendations, commending the senator for establishing the key facts of the disaster.
Titanic Inquiry Transcripts