Houston - Monster storm Harvey hit the south Texas coast late on Friday August 25 and then stalled, gushing torrents of rain over Houston, the country's fourth largest city with six million people in the greater metropolitan area.The storm continues to shower the region as it heads slowly toward the neighbouring state of Louisiana.READ: Houston mayor announces curfew after floodsHow much rain?Up to 94cm of rain fell from Saturday through to Monday evening in parts of coastal Texas, and more than 76cm in Houston.That translates into some 34 trillion litres of rainwater dumped on the region. The National Weather Service said on Tuesday that one rainwater gauge southeast of Houston recorded more than 1.24m - a record for a single tropical cyclone in the continental US.DeathsHarvey is known to have left at least four people dead so far, with six more deaths potentially tied to the storm. The latest confirmed death was that of a Houston police officer who drowned on Sunday while trying to get to work.SheltersMore than 30 000 people were expected to need to stay in emergency shelters.ReliefThe Federal Emergency Management Agency says it is shipping two million litres of bottled water and two million meals into the region. Charities and other federal, state and local agencies will add to that.Economic lossesLosses for the region could range between $30bn and $100bn, according to Bloomberg, mostly from flooding.But much of the damage will not be covered by insurance because flood coverage can be difficult or too expensive to obtain.Data modelling released on Tuesday by Enki Research put the estimated damage figure at $42bn. That would put it among the top five costliest storms in US history.How many need aid?Officials estimate as many as 500 000 people will ask the federal government for aid.