DENVER -- RTD drivers are once again reminded by their supervisors, the importance of putting safety first, after four deaths in five days.

"I sit here and tell you that I'm personally concerned about it," said Phil Washington, Regional Transportation District General Manager.

In an interview with 7News, Washington said these cases are not a breakdown in the system. “This is unprecedented as we see it,” said Washington.

Out of the ordinary or not, the entire agency's safety practices are now being reviewed.

The last time there was a fatal crash where RTD was at fault was in 2007.

Washington said the current safety training is sufficient. “Yes, yes, we think so. We have an extensive amount of training in both with our internal operations and our private contractor operations,” said Washington.

RTD announced on Wednesday that its drivers will soon be getting refresher courses.

Washington said the public should feel safe when riding one of RTD’s vehicles.

“Yes, I think the public can be assured we are safe. Safety is the top priority for this agency," said Washington.

While the circumstances of the crashes may vary, 7News was curious to know if drivers are pressured to keep on a time schedule.

Washington said it’s clear to drivers that safety is the top priority. Any problems are handled on a case by case basis.