At least two people have died and 14 have been injured in Hurricane Harvey, the most powerful storm to hit the US mainland in over a decade slammed into Texas. Throughout the region between Corpus Christi and Houston, many people feared that toll was only the beginning.

Harvey spun deeper into Texas and unloaded extraordinary amounts of rain on Saturday after the once-fearsome hurricane crashed into vulnerable homes and businesses along the coastline.

Harvey made landfall on Friday night as a Category 4 storm and is being reported as the strongest hurricane to hit the United States since Wilma in 2005. Forecasts call for as much as 30 inches of rain to fall in the next few days.

Authorities did not know the full scope of damage because weather conditions prevented emergency crews from getting into the hardest-hit places.

They dreaded the destruction that was yet to come from a storm that could linger for days and unload more than 100 centimetres of rain on cities, including dangerously flood-prone Houston, the nation's fourth-largest.