The worst steamboat accident on the Willamette River happened on April 8, 1854, in Canemah, just above the Willamette Falls (now part of Oregon City). At seven o'clock in the morning, workers were loading freight onto the Gazelle when the vessel's two boilers exploded, killing twenty-four of the sixty people aboard and injuring approximately thirty others. Many of the survivors suffered scalding burns and broken bones, including the Gazelle’s captain, Robert Hereford.

A coroner’s jury found chief engineer Moses Toner guilty of “gross and culpable negligence . . . in knowingly carrying more steam than was safe, and neglecting to keep sufficient water in the boilers.” Some witnesses reported that Toner fled the Gazelle moments before the explosion and escaped prosecution by leaving Oregon Territory.

The Gazelle, a two-engine sidewheeler built by Page, Bacon & Company, was owned by the Willamette Falls Canal, Milling and Transportation Company of Linn City (now West Linn, about eleven miles south of Portland). It had been launched less than a month earlier and was on a route from Willamette Falls to Corvallis. After the accident, the company sold the wreck of the Gazelle, which was rebuilt as the Senorita.

While authorities and newspapers blamed the engineer for Gazelle's explosion, one well-known boat builder and businessman, Jacob Kamm, suspected poor boiler construction was at fault. Early steamboat travel in the West could be hazardous, and boiler explosions were one of the most common causes of accidents.