A package scare at a federal building downtown ended with the box being blown up outside in front of startled eyewitnesses.

Authorities were alerted to the package that was going through an X-ray machine on Wednesday at the Garcia Federal Building and U.S. Courthouse.

The building on East Houston Street and North Alamo is the old federal courthouse. It now houses federal offices, some courts, and a post office.

Law enforcement says that it all started with two men who walked into the building with the intent to mail the package. When it went through an X-ray machine, authorities declared it to be suspicious. SAPD’s bomb squad and the FBI were both called out, but what happened afterwards is what left people shaken up.

Streets were quickly closed off and people were evacuated from nearby buildings, causing a scare.

According to the FBI, the three individuals who brought the package into the building were detained for questioning and were cooperative.

“I just want to make sure the public understands the situation is safe. There was not an explosive device,” said FBI Special Agent Christopher Combs, who added that no one was arrested and everything was done as a precaution. “We don’t take any chances. The SAPD is on it. SAFD is on it. If anything happens locally that may be terrorism, they call us immediately.”

Special Agent Combs also clarified that the three individuals that were detained were not arrested.

By late Wednesday evening, the area had been cleared and was back to normal.