With protection like this, some of us may think we're vastly better off without.
The D.C. fire department is trying to determine why one of its newer diesel ambulances broke down as crews were transporting a patient in cardiac arrest.
It happened on I-295 Wednesday afternoon as Ambulance 19 was taking a shooting victim to the hospital. Then it took several minutes for a second ambulance to arrive.
The driver of Ambulance 19 is telling investigators the indicator lights on the emission control system suddenly and unexpectedly jumped from a warning to shut down in a matter of seconds, and as the engine died, she was able to pull the rig to the side of the road.
The question now is why? And can these newer rigs be trusted to be there in an emergency?
When the D.C. fire department began buying these diesel engine ambulances a few years ago, officials knew they would have to manage them with a new emission control system that would automatically shut the engine down if it wasn't allowed to what's called "regenerate.”
It was a mandate from the Environmental Protection Agency.