Seven weeks after being declared free of the Ebola pandemic, the corpse of a teenager has tested positive for the virus.

The deputy health minister Tolbert Nyenswah, said the samples taken off the corpse of a 17 year old boy had come back positive for the virus.

Liberia was declared Ebola free on May 9, 42 days after the last known case of the disease. Of the three hardest hit nations, Liberia is the only one who successfully kicked off the pandemic, so this new case is a worrying development.

However, Liberian authorities are calling for calm, although there’s still no understanding of how he might have contracted the virus. There’s also no telling who he might have come into contact with before he died.

Officials are taking it very seriously and are trying to see how to contain this new situation. Ebola has killed over 11,000 in Liberia, Sierra Leone, and Guinea, in the worst outbreak of the virus in history.