OCONTO, Wis. (AP) — A house fire in northeastern Wisconsin has killed four people, authorities said.

Firefighters were called to the house in Oconto just before 3 a.m. Friday. Emergency crews arrived to find the house engulfed in flames. Crews were not able go inside until several hours later because the house was unstable.

Authorities are withholding the names of the victims until relatives are notified.

The Oconto School District says counselors are available for students in school offices.