Navaira had surgery Sunday to remove the clot, said agent Joe Casias.

“The next 24 hours are very critical,” Casias said. “….on behalf of his family, we hope his fans will pray for Emilio.”

Navaira and his band Rio had performed at a Houston nightclub on Saturday night. The band’s bus slammed into traffic barrels Sunday just after 5 a.m. on Interstate 610 northbound in the Houston enclave of Bellaire, west of downtown Houston, said Bellaire police Sgt. Daniel Kerr.

Navaira was one of eight passengers on the bus who were injured in the crash, said Houston Assistant Fire Chief Omero Longoria. Navaira was taken to Memorial Hermann Hospital, where he remained in critical condition early Monday morning, said Casey Smith, the hospital’s operations administrator.

Two others were transported to Memorial Hermann with less severe injuries, Longoria said. Both were treated for minor injuries and released, said hospital administrator Lisa Lagrone.

The other five were taken to Ben Taub Hospital, where their conditions were not immediately known, Longoria said. A hospital spokeswoman would not give out any information, citing health privacy laws.

The 45-year-old Navaira and Rio have released more than a dozen albums, including Acuerdate that won the 2003 Grammy for best Tejano album.

According to the band’s Web site, Navaira was born in San Antonio and earned a music scholarship from Texas State. In 1989, he formed the band with brother Raul, who suffered minor injuries in the crash, two Houston television stations reported.