A Bronx woman was arrested Saturday night and charged with manslaughter for starting an apartment fire last month that killed her boyfriend and injured ten others in the building, including a four-year-old boy who lives two floors above her apartment. Investigators say Wendy Walston, 46, set fire to a mattress just before midnight on September 12th. The blaze quickly tore through the apartment and filled the Kingsbridge Heights building, located at 2727 University Avenue, with smoke.

FDNY spokesman Frank Dwyer says Walston “admitted to setting the fire" but it's still unclear if she intended to kill her boyfriend, Thomas Galvin, 50. Galvin escaped the mattress fire by retreating to the apartment's bathroom, where he was overcome by smoke inhalation. One neighbor who escaped the fire via the fire escape tells the Times she was awoken by screaming, and then “the screams got more horrific, and the tone was different."

The injured boy also suffered smoke inhalation and was in a coma for three days, but recovered. It took 100 firefighters to get the two-alarm blaze under control. “This senseless fire took the life of one man, and nearly took the lives of several others,” Fire Commissioner Salvatore J. Cassano said in a statement. “I commend our fire marshals for their relentless efforts to find and apprehend the person responsible for this callous act.”