A minivan crossed an interstate median, flipped and was hit by another vehicle in western Pennsylvania, killing six of seven people on board, state police said Sunday.

After the van came to rest, it was hit by an oncoming car, whose driver was treated at a hospital and released shortly after the Interstate 90 wreck on Saturday, said state police Cpl. Kevin Havern.

The sole survivor in the minivan also was treated at a hospital and released. The cause of the crash was under investigation.

The van was carrying a group of computer programmers from India and their wives on vacation. The software writers worked for Troy, Mich.-based Syntel Inc., an information technology contract services provider, said Jonathan James, vice president for marketing and investor relations.