A video released by the U.S. Forest Service Monday shows how one gunshot started the April 2017 Sawmill Fire that scorched about 45,000 acres in southern Arizona.

The video was filmed by a witness at a gender-reveal party and shows a target that was set up to help reveal whether a newborn would be a boy or girl. A gunshot is heard right before a black square-like target labeled “boy” and “girl” placed over shrubby grasslands explodes and a fire breaks out.

The video initially was obtained from the Forest Service by The Arizona Daily Star in Tucson, which provided it to The Arizona Republic.

In the midst of the dispersing shrapnel, dust and fire, blue smoke can be seen soaring into the air, which usually indicates the expected baby is a boy.

The father, U.S. Customs and Border Protection agent Dennis Dickey of Tucson, pleaded guilty in September to starting the wildfire, according to the U.S. Attorney’s Office in Arizona.

Nearly 600 firefighters and related crews worked the fire, which forced over 100 people to evacuate their homes and caused $8 million worth of damage, previous reports show.

As part of a plea agreement, Dickey agreed to a sentence of five years’ probation and to pay restitution totaling more than $8.1 million. He agreed to make an initial $100,000 payment and monthly payments thereafter, officials said.

Sean Chapman, Dickey’s attorney, told The Star in September that Dickey started the fire during a gender reveal party while his wife was expecting a baby.

Dickey was off-duty at the time and placed Tannerite, an explosive substance, into the target, the U.S. Attorney’s Office said in September.

When the target was shot, the explosion caused a fire that spread into the Coronado National Forest, as well as lands managed by the state and U.S. Bureau of Land Management, and private lands, officials said

In the 49-second video, which redacts the images of two people running near the fire, someone is heard yelling "start packing up" twice.

Dickey immediately reported the fire to law enforcement, cooperated and admitted that he started the fire, the U.S. Attorney's Office said in a press release.

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