SAN FRANCISCO (AP) — Pacific Gas & Electric Co. and others on Thursday appealed a proposed $1.4 billion penalty against PG&E in a deadly 2010 gas-pipeline explosion, in a case that has raised repeated accusations of cozy relations between the utility and state regulators.

Thursday was the deadline for appeals of a California administrative law judge’s recommendation last month for the proposed penalty, which the California Public Utilities Commission says would be the biggest safety-related penalty in its history. The fiery explosion of a PG&E pipeline killed eight people and leveled a residential neighborhood in the suburban San Francisco city of San Bruno. A probe into the blast by the National Transportation Safety Board faulted both the utility and what investigators said was lax oversight by the state utilities commission.