Two people were found dead Wednesday inside a Porsche submerged in a canal near Riverside Drive and Northwest Highway in Las Colinas, police said.
The driver was apparently heading west on Northwest Highway, lost control and flipped off the road and into the water, said Irving police Officer Steve Burres.
"It looks like speed is going to be a contributing factor," he said. "It was completely submerged."
A maintenance worker found the mangled wreckage and notified police. Both victims -- a man and a woman -- were found with their seat belts still on, he said.
A dive team from the Lewisville Fire Department searched the water but didn't find any other victims.
It was unclear when the accident happened.
"I believe it probably happened late at night or early in the morning when traffic is a little less," Burres said. "Otherwise, I think someone would have probably called in on it."
An accident reconstruction team worked for several hours trying to figure out how it happened.
Burres said police had tentatively identified the male victim but were still working to identify the woman.