The U.S. Forest Service has released video footage of the moment an off-duty Border Patrol agent started Arizona’s April 2017 Sawmill Fire by shooting at an explosive target.

Agent Dennis Dickey was taking part in a gender reveal party for his baby when he shot at the box-like target, which read “BOY GIRL” and was rigged to release colored smoke indicating the child’s gender.

In the video, which was taken by a party attendee and later released to The Arizona Daily Star, the sound of a gunshot is heard before the target explodes. Blue smoke can briefly be seen billowing up before flames spread onto the surrounding shrubby grass.

Dickey in September pleaded guilty to a federal misdemeanor charge for causing the fire, which ripped through 45,000 acres of public and private land and caused $8 million worth of damage.

“I feel absolutely horrible about it. It was probably one of the worst days of my life,” he said at the time.

He agreed to pay a total of $8.1 million in restitution, starting with an initial payment of $100,000. He will also spend five years on probation.

Write to Ciara Nugent at ciara.nugent@time.com.