The incident happened Sunday in the home of the victims, who were identified as a brother and sister, both less than 10 years of age, the Boston Globe reported.
"Investigation to this point indicates that the children were found by family members shortly before 8 p.m. enclosed together in a hope chest fashioned with a lid that could only be released from the outside, and not opened from within," Norfolk District Attorney Michael Morrissey's office said in a statement Monday.
Other family members were home at the time of the incident, but "the hope chest was in relatively close proximity to a television that was apparently on with a substantial volume at the time," the statement said.
The incident is currently being considered an accident, prosecutors said.
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