On Monday, May 4, a protest was scheduled to be held at noon, as had been planned three days earlier. University officials attempted to ban the gathering, handing out 12,000 leaflets stating that the event was canceled. Despite this, an estimated 2,000 people gathered on the university's Commons, near Taylor Hall. The protest began with the ringing of the campus's iron Victory Bell (which had historically been used to signal victories in football games) to mark the beginning of the rally, and the first protester began to speak.
Fearing that the situation might escalate into another violent protest, Companies A and C, 1/145th Infantry and Troop G of the 2/107th Armored Cavalry, Ohio ARNG, the units on the campus grounds, attempted to disperse the students. The legality of the dispersal was later debated at a subsequent wrongful death and injury trial. On appeal, the United States Court of Appeals for the Sixth Circuit ruled that authorities did indeed have the right to disperse the crowd.
The dispersal process began late in the morning with campus police official Harold Rice, riding in a Guard Jeep, approaching the students to read them an order to disperse or face arrest. In response, the protesters pelted the Jeep with rocks, forcing it to retreat and injuring one Guardsman in the attack.
Just before noon, the Guard returned and again ordered the crowd to disperse. When most of the crowd refused, the Guard used tear gas. Because of wind, the tear gas had little effect in dispersing the crowd, and some began a second rock attack with chants of "Pigs off campus!" The students lobbed the tear gas canisters back at the National Guardsmen; however, they had put on gas masks upon first throwing tear gas at the students.
When it was obvious the crowd was not going to disperse, a group of 77 National Guard troops from A Company and Troop G, with bayonets fixed on their weapons, began to advance upon the hundreds of protesters. As the guardsmen advanced, the protesters retreated up and over Blanket Hill, heading out of The Commons area. Once over the hill, the students, in a loose group, moved northeast along the front of Taylor Hall, with some continuing toward a parking lot in front of Prentice Hall (slightly northeast of and perpendicular to Taylor Hall). The guardsmen pursued the protesters over the hill, but rather than veering left as the protesters had, they continued straight, heading down toward an athletic practice field enclosed by a chain link fence. Here they remained for about ten minutes, unsure of how to get out of the area short of retracing their entrance path (an action some guardsmen considered might be viewed as a retreat[improper synthesis?]). During this time, the bulk of the students congregated off to the left and front of the guardsmen, approximately 50 to 75 meters away, on the veranda of Taylor Hall. Others were scattered between Taylor Hall and the Prentice Hall parking lot, while still others, perhaps 35 or 40, were standing in the parking lot, or dispersing through the lot as they had been previously ordered.
While on the practice field, the guardsmen generally faced the parking lot which was about 100 yards away. At one point, some of the guardsmen knelt and aimed their weapons toward the parking lot, then stood up again. For a few moments, several guardsmen formed a loose huddle and appeared to be talking to one another. The guardsmen appeared to be unclear as to what to do next. They had cleared the protesters from the Commons area, and many students had left, but many stayed and were still angrily confronting the soldiers, some throwing rocks and tear gas canisters. At the end of about ten minutes, the guardsmen began to retrace their steps back up the hill toward the Commons area. Some of the students on the Taylor Hall veranda began to move slowly toward the soldiers as the latter passed over the top of the hill and headed back down into the Commons.
At this point, at 12:22 PM, a number of guardsmen at the top of the hill abruptly turned and fired their M1 Garand rifles at the students. The guardsmen directed their fire not at the closest students, who were on the Taylor Hall veranda, but at those on the grass area and concrete walkway below the veranda, at those on the service road between the veranda and the parking lot, and at those in the parking lot.[improper synthesis?] Bullets were not sprayed in all directions; instead, they were confined to a fairly limited line of fire leading from the top of the hill to the parking lot. Not all the soldiers who fired their weapons directed their fire into the students. Some soldiers fired into the ground, while a few fired into the air. In all, 29 of the 77 guardsmen claimed to have fired their weapons, using a final total of 67 bullets. The shooting was determined to have lasted only 13 seconds, although a New York Times reporter stated that "it appeared to go on, as a solid volley, for perhaps a full minute or a little longer." The question of why the shots were fired remains widely debated.