Though construction of the hotel proceeded quickly, lasting only two years, and opened on schedule, it was not without its difficulties. Chief among these was a series of bombings meant to destroy the building before it could reach completion. The first such attack was carried out on December 21, 1909, barely six months after construction began. Two men, M. H. Schmidt and David Caplan, attempted to destroy the steel frame of the building with dynamite. While they succeeded in planting and detonating the explosives, the building was not critically damaged, and the destroyed steel beams were easily replaced. The police concluded that the attackers were not especially competent, as they planted the explosives in a poor location and most of the force from the blast was dissipated into the air. Several minor injuries were recorded and windows were shattered up to several blocks from the site, but the hotel remained standing. A second bombing was carried out by the same men on April 15, 1910, but this too was unsuccessful.
The motivation for the bombings seems to have arisen within the ironworkers union. The hotel was constructed primarily by non-union builders, which angered many union workers, both in Utah and on the west coast, and caught the attention of James McNamara, who was involved in a series of similar bombings across the country. While McNamara himself did not carry out the Hotel Utah attacks, Schmidt and Caplan were known to be a part of his operation and participated in his bombings in Los Angeles. In January, 1912, a suitcase full of dynamite was discovered at a storage warehouse in Salt Lake City. The suitcase was deposited there less than a month before the first attack, and police determined that the dynamite used in that attack was taken from this suitcase.
In July, 1919, two men were overheard planning a bombing at the Hotel Utah. The police were alerted and the men fled before they could carry out their plot. No further attempts were made to attack the building, and it is unclear whether this last plot was related to the earlier bombings.