On day of fatal BP refinery blast, 3,712 safety alarms and one unsent email

The findings from a nearly two-year probe by the U.S. Chemical Safety and Hazard Investigation Board provide fresh detail about the accident that killed BP employees Ben and Max Morrissey, both in their 30s.

The new report says the accident resulted from a lack of training, lax safety processes and breakdowns in communication between daytime and evening shift workers.

It says BP failed to shut down refinery production despite repeated warning signs and failed to fix long-known equipment problems that could have prevented the accident at what was then called the BP-Husky Toledo Refinery.

Together, those issues meant that “no effective steps were taken at any point to prevent the fatal accident," investigators said.

The investigators said the Toledo-area accident echoed a 2005 explosion at BP’s Texas City refinery that killed 15 workers and injured more than 170 others. In both cases, BP failed to plan for dangerous liquid overflows. The report said the 2022 accident shows that the company failed to learn the proper lessons from Texas City.

The 2022 explosion and the months leading up to it were the subject of a Page One article in The Wall Street Journal last year.

A BP spokesman said the company cooperated with the investigation and is continually working to improve safety. The refinery is now fully owned by Calgary-based Cenovus Energy, which said it safely restarted production last year and continues to work with regulators to make improvements.

The immediate cause of the accident was a vapor cloud that ignited at 6:46 p.m. after the Morrissey brothers drained naphtha, a highly flammable substance distilled from crude, to the ground. Investigators found that they and other workers were under pressure to improvise as they fought a perilous buildup of liquids.

Workers weren’t fully aware what substances they were handling or how problems earlier in the day had changed refinery operations.

The Morrissey family declined to comment on the report.

The report chronicles a 24-hour period plagued by a series of malfunctions across the refinery, creating what investigators called an “alarm flood" that buffeted workers operating the indoor control room.

The report says 3,712 alarms were recorded over the 12-hour period capped by the explosion and the minutes that followed, calling that more “than a human can effectively respond to." The onslaught drowned out the most critical warnings, causing delayed responses and confusion.

The investigators also found fault with BP decisions made during a monthslong maintenance project before the explosion, during which much of the refinery was shut down.

BP flagged design problems with critical pressure valves and connected pipes but it skipped fixing some of the problems during the 2022 maintenance, concerned the work would delay the restart of the refinery. BP supervisors suggested deferring some of the work to 2027, calling that option “the final resolution of this problem" in internal records, the report says.

The same equipment played a major role in the 2022 accident, when several valves failed, leading to breakages and shutdowns of machinery that then caused additional malfunctions.

Every week the refinery was shut down for maintenance cost money. The plant lost $404.2 million during the first seven months of 2022, more than BP had forecast, by a measure BP calls replacement cost profit that is similar to net income, the Journal reported last year, citing internal refinery documents.

Days after the monthslong maintenance project, BP disclosed in August 2022 that it would sell its half-ownership of the refinery to its partner Cenovus for $300 million.

In the months before he died, Max Morrissey, 34, had told friends and family he was nervous about going to work in part because of safety concerns, the Journal reported. His younger brother Ben, 32, was a new-hire trainee who wasn’t supposed to be at the refinery that night but stayed past his daytime shift to help Max and other workers grapple with persistent operational problems.

“I don’t know how much longer we can let this go…it’s going to tear something up," one machinery operator said over the radio in the morning, 25 minutes before a pipe junction severed, spilling enough naphtha to cause an explosion.

Refinery officials met at around 3 p.m. to talk about the persistent malfunctions with Crude 1, the heart of the refinery’s production machinery, and how to keep processes under control in coming hours.

One person at the meeting wrote an email about the problems and the decision not to shut down Crude 1. But the email was never sent, and details weren’t shared with night-shift workers, leaving them in the dark as they took over before the accident, according to the report.

As problems persisted, the “alarm flood" continued.

“The most frequent alarm went off 22 times in one minute at 6:30 p.m., or on average once every 2.7 seconds, when board operators were already overwhelmed with alarms," according to the report.

During the final hour, the Morrisseys were working together on outside equipment, ultimately draining the liquid that resulted in the deadly naphtha vapor cloud.

The Morrisseys might not have known what they were draining. Other workers believed it was wastewater.

“Just drain it as fast as you guys can," control-room staff told outside workers including the Morrisseys over radios.

“We are," outside workers responded. The report doesn’t identify the speakers.

Separately, BP agreed this month to pay $125,000 to settle violations identified by the Occupational Safety and Health Administration related to the accident. The violations include a failure to ensure emergency shutdown of refinery equipment and insufficient training for workers to respond to naphtha buildup, “thereby exposing employees to recognized hazards."

Write to Jenny Strasburg at jenny.strasburg@wsj.com