Authorities are investigating a fire that ripped through a Melrose building overnight.

The blaze at 1132 Clay Ave., which investigators have deemed suspicious, sent two dozen tenants racing out of their apartments and one person to the hospital with severe burns. Emergency officials say nine other tenants and four firefighters suffered minor injuries, including smoke inhalation.

Tenants say the building's fire detectors didn't go off, and that they were alerted about the fire from neighbors. The building's management company says they weren't aware that any fire detectors were damaged.