WILLISTON, N.D. (AP) — A more efficient system must be established to alert residents of danger in North Dakota’s booming oil patch, an emergency manager and residents said, after authorities failed to alert the public for more than six hours when a facility storing toxic chemicals exploded.

No one was injured or killed in the explosion and fire that started around midnight Monday and raged for much of Tuesday at the Red River Supply plant, located about half a mile from downtown Williston. The blaze shot fireballs into the air and a plume of smoke prompted the cancellation of flights for several hours.