Shuddle Inc., a San Francisco-based human cloud ride-sharing service that transports children in a chaperoned fashion, ceased operations today.

“Over the past two and a half years, we have seen that supporting busy families with safe, reliable, and familiar transportation services is critical to helping families and communities thrive,” the company said in a statement on its website. “We sincerely hope that other family rideshare services can continue successfully on the path that Shuddle helped to forge so that families, schools, and community organizations continue to receive this much-needed support.”

Forbes reported Shuddle raised $10 million two years ago but now can’t find investors.

“We ran out of money,” the San Francisco Chronicle quoted CEO Doug Aley as saying. “This is a capital-intensive business from driver recruitment to customer acquisition.”