Investigators said wet weather caused an accident on Wirt near Westview in northwest Houston.
The crash happened just before 2:30pm.
According to Houston police, the driver was test driving an SUV when he lost control on the slick roadway, hitting a telephone pole and then a tree.
Emergency responders had to rescue the driver from the vehicle. He was taken to Ben Taub General Hospital and is expected to be OK.
Investigators said another accident may have been weather-related, but they are waiting on test results to find out if one of the drivers was intoxicated.
Officials said a Nissan Titan was eastbound on Spring Cypress near Kuykendahl in northwest Harris County around 5pm when it lost control and went into the center lane, striking a Nissan Frontier.
The driver of the Titan tried to correct but then hit a Jeep and spun into a ditch.
Two children in the Jeep were airlifted to the hospital. One of them suffered pelvic fractures and the other had bumps and bruises, officials said. At last check, both were listed in good condition.
Two others in the Jeep were also taken to the hospital for treatment, authorities said, and one other person was injured. Their conditions have not been released.
The 54-year-old driver of the Titan is suspected of being impaired and officials drew blood to run tests.