Top U.S. House investigators announced on Monday that the attempted assassination of former President Donald Trump on July 13th was entirely “preventable,” according to a preliminary report based on expert and witness testimony highlighting multiple security failures that day.

The report pointed to a lack of communication and planning between state and federal agencies, revealing significant gaps in the protection surrounding Trump during a rally in Butler, Pennsylvania, where a gunman was able to fire a rifle round at him from a nearby rooftop.

Fox News cited the initial findings from a House Task Force that outlined alarming shortcomings within the Secret Service.

“Although the findings in this report are preliminary, the information obtained during the first phase of the Task Force’s investigation clearly shows a lack of planning and coordination between the Secret Service and its law enforcement partners before the rally,” the report said.

“Put simply, the evidence obtained by the Task Force to date shows the tragic and shocking events of July 13 were preventable and should not have happened,” the report added.

Task Force Chair Mike Kelly (R-PA) has discreetly issued three subpoenas to local Pennsylvania agencies for “sensitive documents,” according to Politico. These documents are expected to be reviewed and incorporated into a final report scheduled for release this December.

Local authorities have previously disputed claims made by former Secret Service leadership regarding the quality of training and preparation, including which side was responsible for securing the rally’s perimeter where the gunman gained his vantage point.

The investigation revealed that the Secret Service borrowed members of Trump’s detail from other federal agencies. Some of these members received only a brief webinar training before being deployed in the field.

Shortly before 20-year-old gunman Thomas Matthew Crooks opened fire, a breakdown in communication between the Secret Service and other agencies caused “critical pieces of information … [to move] slowly due to fragmented lines of communication and unclear chains of command on July 13,” and the Secret Service “did not effectively verify responsibilities were understood and being executed,” the report states.

There also was no meeting that day between the Secret Service and its state and federal partnering agencies.

The report found that the communication breakdown also hindered agents’ ability to share critical information about the shooter. One notable example of this poor communication involved the initial identification of a suspicious individual, which was not communicated to the agency’s command post until 5:51 p.m.—almost an hour after it was first reported.

Three local officers observed Crooks’s unusual behavior, including the use of a rangefinder, around 5 p.m. that day. “These observations were made independently, and based upon each officer’s experience, Crooks’s behavior and manner were suspicious,” said the report.