AUSTIN (KXAN) — An Austin firefighter was stabbed in the thigh Monday on Interstate 35 after a grass fire near the interstate and Riverside Drive, according to an arrest affidavit.

The Austin Fire Department said Monday the firefighter was recovering at home.

Kelly Dane Ingroum, 59, was arrested and charged with aggravated assault against a public servant. KXAN reached out to an attorney connected with Ingroum. We will update this story if we receive a response.

The affidavit states firefighters saw Ingroum holding “something that was on fire.” They assumed it was a tire because they could smell burnt rubber. Then, firefighters saw him setting more fires as he was walking south toward the Holly Street bridge.

Ingroum dropped the lit item and moved onto the southbound should of I-35 as firefighters worked to extinguish the flames, the affidavit states.

After stopping the fire, the firefighters moved to help Ingroum out of concern he could be hit by a vehicle on the interstate, documents state.

When they got to him on the interstate shoulder, they tried to calm him down and called police to help. However, Ingroum “became agitated” before police could arrive and started crossing I-35, the affidavit states.

According to the affidavit, the firefighters partially blocked off the highway, but there was still traffic passing. The man ran into an open lane of traffic when a firefighter noticed an 18-wheeler coming toward them.

The firefighter “grabbed and pulled” Ingroum away from the interstate lane, the affidavit states. The firefighter told police he and another firefighter held Ingroum to the ground to prevent him from being hit by the 18-wheeler, the affidavit states.

During the altercation, the firefighter noticed a blade, heard his pants rip and realized he had been stabbed in the leg, the affidavit states. The firefighter was taken to the hospital where he was treated for a puncture wound in his left thigh around 2 inches long, the affidavit states

Police found three knives at the scene. One on the ground near the altercation and two on Ingroum, the affidavit states.