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Officials say a fire that raged through one Brooklyn apartment building and spread to another next door has killed two people.

It’s not yet clear what sparked the blaze early Monday in the Williamsburg area. It took about 200 firefighters and about three hours to get it under control.

The police and fire departments say the blaze was reported around 1:35 a.m. in a three-story building on Richardson Street near McCarren Park.

Police say one victim was found on the second floor. There’s no immediate information on where the second person was found, or on the victims’ ages, genders or identities.

Fire officials say two firefighters sustained minor injuries, but didn’t need to be hospitalized.

The cause is under investigation, with some residents reporting hearing an explosion.

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(Source: WABC)