Houston metro rocked by 100 mph derecho that left 4 dead and over ...

HOUSTON - A line of severe thunderstorms swept through southeastern Texas and Louisiana on Thursday, blasting the Houston area with incredible winds reaching up to 100 mph that left at least four dead - including a mother of a newborn - and more than 1 million power customers without electricity.

The extreme wind gusts blew out windows of high-rise buildings and caused transmission towers holding power lines to crumble.

The National Weather Service in Houston called the event a derecho, which produces destructive winds over hundreds of miles and impacts millions of people.

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"Widespread debris, glass and electrical lines are in the streets," the National Weather Service warned Thursday evening.

PowerOutage.us reported that more than 800,000 people in the Houston metro area lost power, but with nearby counties also dealing with outages, the state’s tally climbed to well over 1 million customers at the storm's peak. 

NWS storm survey teams said much of the damage across much of the Houston area was straight-line winds from extreme thunderstorm downdrafts, though one tornado was confirmed near Cypress. 

The strongest gust recorded by a wind gauge was 78 mph in the Highlands neighborhood, but based on the extent of damage, survey teams estimated thunderstorm gusts reached 90-100 mph in Baytown, while Downtown Houston had "significant" straight-line winds peaking at 100 mph. 

The investigation into the intensity of the Cypress tornado was still in progress early Friday afternoon. 

"It was kind of crazy — I was up in my bedroom and all of a sudden my alarm starts going off: ‘Tornado Warning! Tornado Warning! Take shelter,’ " Juan Alcala, who was visiting Houston form Austin, told FOX Weather.  "All of a sudden everything just turns dark, and you could see outside the wind started coming in, and the rain — it was just dark."

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Mother of newborn among 4 killed by storm

Houston Mayor John Whitmire said at least four people were killed by the storm, and state resources were being requested to help with the recovery. At least two were killed by falling trees, and a third was killed by a falling crane, officials said.

A 31-year-old woman who had recently given birth to her fourth child was killed when a tree fell across their car in their driveway, according to FOX 26 Houston. The station reports the woman had concerns about the stability of the tree in the storm and had gone out to the car to move it out of the way when the tree toppled, pinning her inside.

A 73-year-old man was killed while working inside a cement truck when a crane toppled into the cab, FOX 26 reported. 

"We had a storm with 100 mph winds — the equivalent of Hurricane Ike. (There's) considerable damage downtown," Whitmire said during a press conference Thursday night. "We had firefighters taking live wires off (Interstate) 290 that was blocking thoroughfares."

Whitmire warned that 2,500 traffic lights across the city were down, "and they will be down for considerable hours."

METRO Houston reported several disruptions to its METRORail lines, with debris covering tracks in several locations. Bus shuttles were providing emergency service, but officials warned that bus routes were encountering significant delays and detours due to damage around the city. 

"We’re absolutely focused right now on trying to deal with the numerous roads that are blocked by fallen trees, power lines, and debris from some of the structures," Harris County Sheriff Ed Gonzalez told FOX Weather. "So we’re coordinating with some of the different crews that are going to be out there so we are asking everybody to be patient as they navigate around some of the slow traffic."

‘Rain and debris poured into the lobby’

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The local National Weather Service office issued several Tornado Warnings for the Houston metro on Thursday evening, but by the time the storms cleared, strong winds were believed to have caused most of the damage.

"The roof of the Hyatt Regency downtown blew out," a customer at the hotel told FOX Weather. "Rain and debris poured down to the lobby."

He said staff were doing their best to keep people safe and away from the debris.

Windows appeared to be blown out in other downtown buildings, including around the Wells Fargo Plaza. 

The broken glass and debris forced city leaders to implore non-essential downtown workers to stay home on Friday and ask business owners to be flexible with employee absences.

In nearby Minute Maid Park, wind and water were seen blowing into the building, but the severe weather did not appear to affect the play of the Astros baseball game.

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"It is all hands on deck tonight…Downtown is a mess, so stay at home tonight and tomorrow," Whitmire said.

Local residents described the storm's impacts as hurricane-like despite the severe weather lasting less than an hour.

Due to the severe weather, ground stops were also issued at Bush Intercontinental Airport and Houston William P. Hobby Airport. At the peak of the storm, gusts at both airports reached 62 mph.  A gust of 71 mph was clocked in College Station, while Cypress hit a gust of 65 mph. 

The Houston school district closed all public schools on Friday and said they would reopen Monday. 

The dangerous thunderstorms were expected to transition into a flood threat during the overnight hours as already saturated grounds were expected to receive an additional 2-5 inches of rainfall.

Dangerous heat returns as hundreds of thousands remain without power

While the storms' clouds and rain kept temperatures in the low 80s Friday, the return of late springtime heat looms for Houston this weekend into next week, leaving the hundreds of thousands still without power with the daunting reality that they may not have air conditioning.

According to Harris County Executive Judge Lina Hidalgo, 10 energy transmission lines are down.

"If you are tied into the transmission lines that fell… just like in (Hurricane) Ike, you are going to have to go a couple of weeks, most likely, without power," Hidalgo said. 

Highs on Saturday and Sunday are expected to climb back into the low 90s around Houston, and with typical humid Gulf air in place, heat index readings are expected to reach the mid 90s.

"We are looking at a multiday event," said Paul Lock with Centerpoint Energy. "If you depend on life-saving equipment, you need to make plans now to find another place to stay."

84 mph wind rakes New Orleans as storms sweep Gulf Coast

The line of severe thunderstorms continued their march across the Gulf Coast Thursday night into early Friday morning, leaving a trail of wind damage and power outages there in their wake.

Tens of thousands lost power in New Orleans, part of 200,000 power outages in Louisiana during the peak of the storm.  New Orleans International Airport recorded two gusts of 84 mph and another gust of 76 mph, as New Orleans’ Lakefront Airport recorded a gust of 82 mph.  Accompanying heavy rains left some streets and underpasses flooded around the New Orleans area.