Updated

Sen. Jay Rockefeller is asking the Obama administration to update the families of miners killed in West Virginia's Upper Big Branch mine explosion on the government's investigation.

The West Virginia Democrat says families of the 29 miners haven't been briefed since September. He says in a letter to U.S. Labor Secretary Hilda Solis that that's too long.

Rockefeller also wants an update.

The April 5 explosion was the deadliest at a U.S. coal mine since 1970. The Labor Department's Mine Safety and Health Administration is conducting a civil investigation, while the U.S. Department of Justice is conducting a criminal probe. Mine owner Massey Energy has denied doing anything wrong.

The Labor Department said it intends to meet with the families after the holidays.