Authorities are investigating what caused two trains to collide Tuesday, leaving two crewmembers hurt and more than 20,000 gallons of lubricant oil seeping onto the ground.

The crash, which occurred in the afternoon near the small town of Dublin, in western Virginia, caused 18 cars and a locomotive to derail, Norfolk Southern spokeswoman Susan Terpay told The Associated Press. The oil leaked from one car, while scrap metal spilled from another.

Both Norfolk Southern trains had been traveling in the same direction when one rear-ended the other.

As the scene unfolded, it appeared the crash had been much bigger than the company had initially reported. Instead of five empty cars and a locomotive derailing, it was later discovered that eight cars on the first train had flown off the tracks, as did 10 on the second train.

Ms. Terpay said the crewmembers were treated at a hospital and released, and all other derailed cars were empty.

Norfolk Southern has said that contractors are still working to clean up the spillage, but all oil had been contained onsite.

Residents of Dublin are accustomed to the daily sounds of trains passing through, Teresa Frank told The Roanoke Times. But when she heard the crash, it was so loud she immediately stopped what she was doing – picking green beans in her father’s yard – and started running back into the house.

“I didn't know what it was, but we started seeing emergency cars show up,” said Ms. Frank.

The derailed train cars ended up in the backyard of another resident, Kenny Trail. He told The Roanoke Times that he’d been watching TV when he heard the noise outside. The train destroyed his only form of transportation, an electric scooter, and he was evacuated, reported the newspaper.

Get the Monitor Stories you care about delivered to your inbox. By signing up, you agree to our Privacy Policy

The oil that spilled in this crash is a non-toxic lubricant commonly used in machinery, emergency responders told local CBS affiliate WDBJ.

This reports contains material from The Associated Press.