Officials said the man did not appear to be targeting Trump or others involved in the trial
The fire at the Henri Mondor hospital in Creteil broke out late on Wednesday night and was eventually brought under control in the early hours of Thursday morning.
The cause of the fire has not yet been determined.
“The fire in the residential block within the Henri Mondor hospital complex has now been brought under control thanks to the intervention of firefighters,” Paris public hospitals chief Martin Hirsch said on Twitter.
“We regret to say that there has been one death,” he said.