1 dead, at least 11 injured following tornado in Rio Grande Valley: NWS

At least one person was killed and 11 others were hospitalized with injuries Saturday morning after a tornado touched down near Laguna Heights, Texas, in the Rio Grande Valley, according to officials.

"The Laguna Madre area was hit by its fourth weather event in as many weeks. Overnight, a tornado caused extensive damage to Laguna Heights, the community between Port Isabel and Laguna Vista on Highway 100," the City of Port Isabel said in a statement.

A preliminary damage assessment indicates that an EF1 tornado damage with wind speeds around 86 to 105 miles per hour, possibly up to 110 miles per hour, occurred Saturday morning just after 4 a.m. in Laguna Heights, according to the National Weather Service.

A disaster declaration has been issued. A gas leak has been repaired and some power has been restored in the area, but not all, according to Cameron County officials.

Violeta Flores-Tovar confirmed to ABC News that her brother, Roberto Flores, died as a result of the EF1 tornado event in Laguna Heights, Texas. She also confirmed a nearby trailer was lifted during the storm and landed on his home.

"He was a loved brother, a recent father to his son Christopher Flores. He will be missed by many family, and friends," she said in a statement.

In a statement on Facebook, the Port Isabel Police Department confirmed there were injuries on the ground and that multiple structures had been destroyed. No traffic will be allowed through Laguna Heights.

"Crews are working to clear debris and downed power lines," the statement said. "At about 4 am, a tornado struck the Laguna Heights area. Multiple structures destroyed and injuries confirmed. Port Isabel Event Center is open for shelter."

Drivers on Highway 100 will be rerouted onto Highway 48, according to police.

Storms may bring damaging winds, large hail and scattered tornadoes to southern Texas and there is a high flooding risk. A flood watch is in effect through Sunday afternoon for a large area stretching from Brownsville at the southern tip of Texas, all the way into central Oklahoma, the NWS said.

Chances of showers and thunderstorms will increase Saturday and through the weekend across Deep South Texas. The heaviest rainfall is expected to fall Saturday into Sunday.

This is a developing story. Please check back for updates.