This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

Update: In an effort to assist law enforcement, the Riverview Gardens School District will be closed Thursday, September 8th.

Please enable Javascript to watch this video

ST. LOUIS, MO (KTVI) - The St. Louis Bomb and Arson Squad was called to Moline Elementary School in the Riverview Gardens District Wednesday afternoon, after a small explosion happened inside a suspicious package dropped off near an exit door at the front of the school at about noon.

The package had been left by an unknown man shortly before the explosion, which some say sounded like fireworks.

Then black smoke was seen coming from the bag.

No one was hurt.

But very quickly after the boom was heard, the roughly 400 students and staff inside the building were evacuated.

They walked a few blocks to nearby Westview Middle School, where parents came to pick up kids who do not ride the bus.

The district got word to parents quickly using an automated phone message system.

'I was near it and we had to run to get out,' said third grader Bro`klyn Johnson. 'We ran towards the back door where we go out to the playground and we went all the way down to the gate so we would be safe,' he said, adding, 'it was scary.'

Shortly after 3:30 p.m., Bomb and Arson detectives blew up the suspicious package using a robot.

After the blast, some sort of electronic device was found to have been in the package, but no bomb.

Superintendent Scott Spurgeon says he is proud of how the staff and kids handled the emergency. But he finds it all very puzzling.

'You always have to ask yourself why, especially at an elementary school. And why we have to continue to deal with things like this. Our children are in school to be educated, not to have to be evacuated because of something challenging and scary such as this,' he said.

Suspect left pkg at NoCo elem school. Staff heard "firework".School evacuated & some nearby neighborhood. @FOX2now pic.twitter.com/yvopjKJj0l — Joe Lamie (@GIJoter) September 7, 2016

Suspicious pkg being looked into at Moline Elementary in #NorthCo. All kids are evac'd & safe. Bomb & Arson detectives investigating. — St. Louis County PD (@stlcountypd) September 7, 2016

Handling an incident in the 9800 block of Winkler in #NorthCo. Pls avoid the area while we investigate. — St. Louis County PD (@stlcountypd) September 7, 2016

38.74812 -90.265358