Rockaway Township Mayor Michael Dachisen died Wednesday night. He was 58.

Dachisen, who was embroiled in an ongoing feud with fellow Republicans on the township council, failed to show up as expected at a Wednesday night opioid seminar in the township.

Sources said the mayor went into cardiac arrest Wednesday night and was taken to St. Claire’s Hospital in Dover where he passed away.

The mayor had been fighting with the council majority over alleged lack of transparency and for taking township health benefits. The squabble made its way to court and a ruling on one aspect of the litigation is set for Friday in state Superior Court, Paterson.

Dachisen long had been publicly silent, but just recently spoke out against his critics in the form of a lengthy electronic statement.

Late Wednesday night, Council President Jeremy Jedynak issued the following statement:

“It is with great sadness that the council learned of Mayor Dachisen’s passing this evening. … At this time, we ask for your prayers, especially for Mayor Dachisen’s loved ones that they have strength and comfort during this difficult time.”