A growing number of House lawmakers are calling for a congressional investigation into the inter-agency communication debacle that led to the emergency evacuation of the U.S. Capitol complex on Wednesday evening.

The lawmakers are stunned that an Army paratrooper stunt at the Washington Nationals baseball stadium — a pre-planned event that allowed a small, twin-engine plane to enter highly restricted airspace near Capitol Hill — could trigger so much chaos even as Washington law enforcement agencies are under heavy pressure to improve security protocols following the deadly attack on the Capitol last year.

While the Federal Aviation Administration (FAA) was aware that the Army aircraft would be circling Nationals Park, roughly a mile south of the Capitol, the agency did not inform the U.S. Capitol Police, according to the police department and lawmakers. The communication failure prompted the USCP to issue a startling evacuation order warning that the unidentified aircraft “poses a probable threat to the Capitol Complex.”

The order was quickly reversed, and the FAA says it’s investigating the mishap. But a number of lawmakers think a congressional probe is also merited.