TULSA, Oklahoma - A man is in jail and his dog is dead after police say he started a fire in his own apartment. 

Tulsa police arrested William Wagner for first-degree arson after investigators said he set his own apartment on fire at the Beaumont Cove complex near 31st and Garnett.

A woman who lives next door said after the fire started, the man who lives there went inside her apartment and started going through her fridge.

"I got halfway out the door and all I see is smoke and the first thing I do is grab my kids," said neighbor Brooke Klotzke.

Brooke Klotzke said her first concern was that the fire would spread to her apartment.

"It was scary,” she said. 

She said Wagner made his way inside her apartment and into her kitchen. 

"He grabbed the juice right there that's over there, sitting and he starts drinking it like it was his," Klotzke said. 

She said he didn't stop there and started making a mess of her apartment. 

"There's trash all over the floor," she said. 

Once the flames were out, fire investigators questioned Wagner and had him empty out his pockets.

"Multiple sets of keys, lots of paperwork," said Tulsa Fire Captain Howard Whitehill. 

While no one was hurt, firefighters say they found Wagner's dog inside, dead. 

"Brought it out, tried to save it the best they could, but it is deceased," said Howard. 

Klotzke said she's only lived in the apartment for a few months and hasn't interacted with Wagner much so his behavior surprised her. 

"He didn't seem like it bothered him," she said. 

Investigators are working to figure out exactly how the fire started.