Authorities in Fresno are investigating an incident in which at least one man broke into the Foster Farms chicken shed and used a golf club to kill 920 chickens.

“Whoever did something like this is pretty sick,” Deputy Chris Curtice told the Los Angeles Times. “It would take a long time to do it… People should be alarmed at something like that.”

According to a Fresno sheriff’s department release, authorities arrived at Foster Farms in Caruthers shortly before 8:30 a.m. on September 20 and discovered the suspect(s) had pulled a fence back to gain access to the chickens. 

While inside, the suspect used a golf club, and “possibly another similar type instrument,” to kill 920 chickens. Foster Farms estimated the monetary loss at about $5,000.

“It is the express policy of Foster Farms to treat its birds humanely and with compassion,” Foster Farms said in a statement. The company is offering a $5,000 reward for information leading to the suspects’ arrest.