WALNUT CREEK, Calif. -- BART's since-suspended "simple approval" practice was the probable cause of an accident that killed two track workers in Contra Costa County in 2013, the National Transportation Safety Board said in a report issued this week.
The NTSB adopted its report Monday in the case of Christopher Sheppard, 58, of Hayward, and Laurence Daniels, 66, of Fair Oaks, who were struck and killed on Oct. 19, 2013, while inspecting a dip in the tracks between BART's Walnut Creek and Pleasant Hill stations.
The northbound train had no passengers on board and was being used for training of management employees to work as substitute operators and system maintenance workers during a strike by BART's two largest unions.
The "simple approval" practice had track workers get authorization from BART's control center to enter the trackway "with no additional protective measures or restrictions provided," the NTSB report said.
"Under simple approval, roadway workers were required to be aware of train and equipment movements and provide their own protection," the report said.
Workers were prohibited from entering the BART right-of-way without a "watchman" whose sole responsibility was to watch for approaching trains, according to the NTSB report.
When the minor defect was found on the tracks near Walnut Creek, Sheppard, a BART manager, and Daniels, a contractor working with the agency, went out to take measurements, the NTSB report said.
The train that hit the workers left the Walnut Creek station and was traveling at 68 mph within 28 seconds. At 1:44 p.m., the operator trainee on board repeatedly hit the red emergency stop button and shouted, "Look out!" and "No, no, no!" but the train hit the workers 4.7 seconds later, the NTSB report said.
The day after the deaths, BART issued a memorandum prohibiting simple approvals and said trains in work areas must slow down to a maximum speed of 27 mph.
A month after the death, the NTSB made urgent safety recommendations to the Federal Transit Administration to require "redundant protection" for track workers, such as a safety monitoring system known as positive train control or secondary warning devices.
The California Public Utilities Commission has also since prohibited access to the right-of-way that was allowed under the simple approval practice.
In April 2014, the California Division of Occupational Safety and Health fined BART $210,000 for safety violations in the incident.
BART officials said they would be releasing a statement later Tuesday afternoon on the NTSB report.