AMA Pro Motorcycle-Superstore.com SuperSport Race Two at Road America has been postponed until the end of the day Sunday after two red flag incidents, including one brought out by a huge pileup just after the race was restarted.

The original start of the race was halted on lap two when Patricia Fernandez, Max Flinders and Quentin Wilson crashed at the Bend and David Sadowski, Jr. crashed at Turn 13. Wilson and Sadowski both needed medical attention.

The remainder of the field was lined up for a complete restart, but as the bikes left the grid riders at the front of the group lost control and crashed, leading to a chain reaction series of crashes and some fallen riders being hit by motorcycles. When the dust settled a total of eight riders had crashed, including Race One winner Corey Alexander, Hayden Gillim, Shawn Hill, Roi Holster, Tyler Linders, Caroline Olsen, Alex Shaw and Ricardo Valdez, according to AMA Pro Racing.

Several of the riders needed medical attention, including Holster, Linders, Olsen and Shaw. The conditions of the riders involved in the incident were not immediately known.

The incident required an extensive cleanup, and officials postponed the race until the end of the day Sunday.

More details will be reported as they become available.

UPDATE: AMA Pro Racing has corrected its initial announcement. Corey Alexander was not involved in this incident.