steamer J. C. Swan delivered the Confederate aid: two 12-pound howitzers, two 32-pound siege guns, 500 muskets, and ammunition, in crates marked as Tamoroa marble. The Confederates captured the munitions when they seized the Federal Baton Rouge Arsenal. Militia officers met the shipment at the St. Louis riverfront and transported it to Camp Jackson, inland. Conflict Lyon suspected the Camp Jackson forces of conspiring to attack the arsenal. His suspicions were confirmed by personal investigation after he visited Camp Jackson, allegedly disguised as an older woman. On May 10, Lyon marched on Camp Jackson with about 6,000 Missouri Volunteers and U.S. Regulars. Lyon forced the surrender of the militia, taking 669 prisoners. Lyon placed the captured soldiers under arrest and began marching them under guard to the arsenal, where they were paroled and ordered to disperse. But the long march was seen as humiliating by pro-secession residents of the city. Angry secessionists shouted insults at the Union troops and threw rocks and debris at them. Units composed predominantly of ethnic Germans were particularly targeted, with shouts of "Damn the Dutch!" This eventually led to gunfire. Exactly what provoked the shooting remains unclear, but the most common explanation is that a drunkard stumbled into the path of Lyon's marching soldiers and fired a pistol into their ranks, fatally wounding Captain Constantin Blandowski of the 3rd Missouri Volunteer Infantry. The Volunteers, in reaction, fired over the heads of the crowd, and then into the crowd. Some 28 civilians were killed, including women and children; more than 75 were wounded. General Frost reported that his command was "deprived of their arms, and surrendered into the hands of Captain Lyon. After which, whilst thus disarmed and surrounded, a fire was opened upon a portion of it by his troops, and a number of my men put to death, together with several innocent lookers-on--men, women, and children." The incident sparked several days of civil unrest in St. Louis. On May 11, Volunteers were fired upon from windows at 5th and Walnut streets; they returned fire at the mob. Colonel Henry Boernstein, commander of the 2nd Missouri Volunteer Infantry and publisher of the Anzeiger des Westens, a German-language newspaper in St. Louis, remarked in his memoirs that he gave several of his men leave to visit their families on the morning of May 11 and that "Most of them did not return... until it grew dark,