SALT LAKE CITY — A pair of rollovers involving large trucks slowed the morning commute Thursday for some motorists.

The first accident was on U.S. 40 near the bottom of Daniels Canyon outside Heber. Just before 3 a.m., a truck hauling crude oil was traveling westbound when the trailer flipped onto its side, said Utah Highway Patrol spokesman Cameron Roden.

The trailer, which was carrying 50,000 gallons of oil, began leaking, he said. The leak has since been contained. The health department was on scene at the accident, as well as law enforcement.

Crews needed to drain the trailer first before up righting it, Roden said. Traffic was routed to the eastbound lanes all morning. Both lanes were expected to reopen by noon, he said. No one was injured in the incident.

A second accident happened about 6:45 a.m. on eastbound I-80 near 5600 West. A dump truck hauling salt flipped onto its side and fell into the median, Roden said. Some witnesses reported seeing sparks under the truck prior to the accident, he said.

Investigators on Thursday were looking at whether the truck suffered a mechanical failure, if the driver possibly had fallen asleep at the wheel or if a combination of both contributed to the accident.

The driver was taken to Intermountain Medical Center with minor injuries, Roden said. Eastbound traffic was closed until about 8 a.m. while the salt was cleaned up. One lane of eastbound traffic was reopened about 9:30 a.m.