The Illinois National Guard said Scott Williams, a firefighter and paramedic, has died in the line of duty in Lemont.
Williams, who served with the Illinois National Guard for 15 years, died after responding to a call at the Argonne National Laboratory Fire Department, the National Guard said in a Facebook post.
Firehouse News reported Williams went to investigate reports of smoke in one of the laboratories at the facility on Saturday. He was found unresponsive in his living quarters the next day, the news site said. Williams had deployed to Afghanistan during Operation Enduring Freedom, according to the National Guard. He was also a member of the Wilmington Fire Protection District since June 2017, the district said on Facebook. He also served previously with the Minooka Fire Protection District.