Probable cause
While conducting the safety briefing, the forward flight attendant was thrown backwards into the flight deck door due to the sudden stopping of the airplane by the flight crew to prevent a collision with a bus.
Contributing to this accident was the bus drivers difficultly in observing the airplane moving towards the roadway.
NTSB analysis
According to the flight crew, just after they began to taxi, they observed a bus passing in front of the airplane requiring the captain to suddenly apply the brakes to avoid colliding with the bus. The captain immediately called the flight attendants (FA), who were conducting their safety demonstration, to check on their condition and the condition of the passengers. The forward FA indicated that he had been thrown backwards into the flight deck door but was alright to continue with the flight. While enroute to Denver, the forward FA informed the flight crew that he was a little sore, but he and the rest of the FAs were fine to continue their return flight to Detroit. However, after arriving in Detroit, the forward flight attendant sought medical treatment and was diagnosed with a broken rib.
According to the operator, the Delta employee bus was in the process of training new drivers. There are four roadways that cross the taxi lanes between the two terminals. At the time of the accident, the only policy was to stop at the stop sign and visually confirm it was safe to cross the taxi lanes. A review of video from the bus showed that it stopped at the stop sign and then proceeded to cross the taxi lanes. The video shows that from the perspective of the bus driver, it is difficult to see the area in which the airplane was parked from the roadway and the 45-degree pushback made it difficult to observe the airplane moving towards the roadway. As a result of this event, Delta implemented a restriction on vehicle crossing the taxi lanes when there are airplanes in the vicinity of the roadway.
Text from the NTSB. Open the NTSB docket for DCA21LA184 for the full record.
Event
- Date
- Jul 22, 2021
- Type
- Accident
- Place
- Romulus, Michigan
- Nearest airport
- Detroit Metropolitan Wayne Cou (KDTW)
- Highest injury
- Serious
- Serious injuries
- 1
- Weather
- Visual (VMC)
- Light
- Day
Airbus A321-211
- N-number
- N376DN
- Category
- Airplane
- Year built
- 2019
- Operating rule
- Part 121 (airline)
From the NTSB aviation accident database: N-registered aircraft, events since 2008, data through Oct 28, 2026. The file is published monthly, so the latest weeks are incomplete and recent records can change. The official source is the NTSB aviation investigation search. CheckAero is independent and not affiliated with the NTSB.