Traffic was backed up on Interstate 55 near Springfield for several hours Thursday morning after two semis collided with each other.

According to the state police, Juan Diaz of San Angelo, TX, was driving a semi north near milepost 93 when his truck collided with a trailer of a semi in front of him. Officers said Diaz failed to slow down to avoid the semi, as it was slowed because of traffic ahead of it.

Diaz, 50, had to be extricated from his truck by the Springfield Fire Department. He was taken to HSHS St. John's Hospital in Springfield by helicopter with serious injuries.

37-year-old Valentin Pavlyuk of Vancouver, WA, was driving the leading semi. His passenger was 29-year-old Julia Pavlyuk. No injuries were reported for either of them, and police said they were both wearing their seat belts at the time of the incident. It is not known whether Diaz was wearing his seat belt or not.

The incident occurred at 9:38 a.m. Thursday. It remains under investigation by the state police.