PHILADELPHIA (CBS) — A young girl dies following a sleepover in Northeast Philadelphia on Wednesday morning.

Police say a neighbor found an 11-year-old girl unresponsive during a sleepover on the 9200 block of Angus Place around 10:15 a.m.

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The girl was transported to Aria-Torresdale Hospital and pronounced dead at 11:20 a.m.

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The girl was spending the night at a friend’s home just two doors down from her own.

Investigators have been in and out of the home where she was found, trying to figure out if there may have been an underlying medical condition.

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There is no word yet on how the girl died.