A truck leaking engine oil across a road in Taoyuan's Zhongli district sent six morning commuters on motorcycles crashing to the ground — bad for the riders, and now a criminal case for the driver.

• A big patch of engine oil spread across a road junction early Wednesday morning, making it dangerously slippery.
• Six riders, five men and one woman, fell one after another and were hurt; three went to hospital with scrapes and cuts.
• Police tracked the source through security cameras to a freight truck driving from Kaohsiung to an industrial park in Zhongli.
• The oil filter cover on the truck had cracked, spraying oil onto the road as it drove.
• The 45-year-old driver has been referred to prosecutors on a public endangerment charge and also faces a traffic fine.

Outlook: The case now moves to the Taoyuan prosecutors' office, with police urging drivers to check their engines and oil lines before setting off.