The initial explosion occurred Friday at Argenta Hall while a contractor was working on the boiler that had developed mechanical problems and was shut down earlier in the week, state Fire Marshal Bart Chambers said.
Preliminary information showed the initial blast started a small fire that was extinguished by sprinkler systems.
Chambers said natural gas started leaking from a 3-inch-diameter feeder line to the boiler, but investigators have not yet determined how the gas ignited.
The boiler in question had no history of safety violations or active inspection issues, he said, noting it was last inspected 18 months ago in compliance with state codes mandating checks every two years.
Shannon Ellis, UNR vice president of student services, said students, faculty and staff members were “feeling incredibly grateful that there were no serious injuries and no lives were lost.”
Argenta will remain closed for at least a year, possibly two. Nye Hall, a neighboring dorm damaged by the explosion, will stay closed into the fall, Ellis said.
About 200 students have been displaced and school officials were trying to establish living arrangements for 1,300 students expected for the fall semester
