The downtown branch of the Hartford Public Library is closed on Tuesday after a transformer blew and sparked a fire, according to the mayor’s office.

The mayor’s office said there was a report of an explosion and smoke in the basement at 500 Main St. just after 9:32 a.m., power was out, and emergency crews responded.

They found heavy smoke and an electrical unit was on fire.

They later determined that a transformer in the basement had blown and caused a fire.

The mayor’s office said they Hartford Fire Department, Hartford Police Department and Eversource isolated the issue, contained the fire and brought the situation under control at 10:43 a.m.

Eversource said none of their transformers were on fire and all of their transformers are operational.

“During our investigation, we determined that customer-owned equipment failed, leading to the outage at the Hartford Public Library and Hartford City Hall.  Our crews remain on scene and continue to coordinate with the city to evaluate the repairs that need to be made,” Eversource said in a statement.

No injuries are reported.

“We’re incredibly grateful to our first responders for their quick, coordinated response,” Hartford Mayor Arunan Arulampalam said in a statement. “We’re continuing to work closely with our public safety teams and Eversource to monitor the situation and ensure that power is safely restored to impacted areas.”

The library and the city are looking into ways that the can reopen as soon as possible.

“We’re incredibly grateful to our first responders for their swift and coordinated efforts,” Bridget E. Quinn, Hartford Public Library president and CEO, said in a statement. “I would also like to extend my heartfelt thanks to our dedicated Library staff for their commitment to safety throughout this challenging situation. We continue to work closely with the City of Hartford, our public safety partners, and Eversource to monitor developments and ensure power is safely restored to all affected areas.”