LONGVIEW, Wash. (AP) — The implosion of a chemical tank at a pulp and paper mill in Washington state Tuesday killed an undisclosed number of people, local authorities and company officials confirmed.

In a joint statement, Nippon Dynawave Packaging Co. and local law enforcement said the tank’s rupture caused “multiple critical injuries” as well as fatalities.

Authorities said there was no immediate threat to the public.

Mike Gorsuch, battalion chief with the fire department in Longview, Washington, described it as a “mass casualty scene.” He said first responders had decontaminated patients and taken them to hospitals in Longview and Vancouver, Washington.

The Nippon Dynawave Packaging Co. facility is a pulp and paper mill and liquid packaging plant that makes material for tissues, printing paper, cups, plates, cartons and other goods. It employs about 1,000 people, according to the Washington State Department of Ecology.

About 40 firefighters and paramedics had responded, along with a regional hazmat team, Gorsuch said. The incident was reported at 7:19 a.m.

Nippon Dynawave did not immediately respond to a request for comment.

Thousands of residents of southern California remained evacuated Tuesday due to a damaged chemical tank at an aerospace plant.