There were more than 200 passengers on the Blue Line train at the time of the crash. At least 14 people on the train, including the operator, suffered minor injuries and were taken to a hospital.
"We were carrying around 230 people, some of the people complained about minor injuries," said Metro spokesman Jose Ubalvo.
The impact knocked the front car of the electric train off the track. The other cars remained on the track, which reopened about three hours after the crash.
The bus, which is also operated by Metro, sustained heavy damage. It looked like it had been broadsided by the train. Fortunately, there were no passengers on board the bus because it was being test driven.
"It was a bus that was auto-serviced, driven by our Metro mechanic, that was going southbound on Griffith and that's where this accident happened," said Metro spokesman Luis Inzunza.
Authorities are trying to figure out exactly why the bus turned in front of the train. The wreckage has been cleared away and Metro service is back to normal.