A fire that killed an inmate at Indiana State Prison in Michigan City was ruled accidental this week.

The fire itself is believed to have been caused by Joshua Devine, who was serving a 16-year prison sentence for attempted robbery when he was burned to death on April 9, according to ABC 57.

The Indiana Department of Corrections says the fire started along the wall of Devine’s cell near the television. Devine died of thermal burns and it’s believed that he was altering electrical equipment in his cell, according to prison officials.

“At 9 p.m. our officials went through our standard count time. Count is where all offenders are physically observed and counted or we have that 5 times a day, and everything was fine at 9 p.m.” said Pam James, spokesperson for Indiana State Prison.

The fire started about 45 minutes later. The prison was on lockdown for afterwards.