It's been almost two days since Hurricane Harvey made landfall in Texas, and yet its path of destruction only seems to be growing. Here is what you need to know about the damage and what you can do to help.

What's happening?

Hurricane Harvey, which was first named a Tropical Storm on August 17, made landfall in Texas on Friday night. It is the strongest hurricane to hit the U.S. in more than a decade and has wreaked havoc on the communities in its path — especially Houston, the fourth most populous city in the nation. Flooding in the city has already reached "unprecedented," "catastrophic," levels, and is only expected to get worse, potentially reaching as much as 50 inches of rain by the end of the week, according to experts.

Who is at risk?

While all residents of Houston and surrounding areas should follow precautions for staying safe, there are several populations who are particularly at risk under these circumstances.

Houston has had great success reducing rates of homelessness in the city, about 3,400 people remain homeless in the city — many of whom were still vulnerable to the storm despite efforts of the Red Cross and other local organizations to help them find shelter.

Additionally, while the Weather Service is recommending that people go to their roofs for rescuing rather than staying in their attics, this is difficult if not impossible for many individuals with disabilities as well as elderly people — especially those who live on their own and/or have little support.

What's being done?

First responders have already received, and are attempting to address, thousands of calls and Governor Greg Abbott activated 3,000 National Guard troops, who will join the efforts of 600 boats already aiding rescue efforts and at least 16 helicopters the Coast Guard deployed for air rescues.

What can you do?

If you live in the Houston area, residents with high-water safe boats are being asked to help with rescue efforts. If you don't live in Houston, you can help support organizations that are currently on the ground, like the American Red Cross. Global Giving has also set a $2 million crowd-funding goal to support local relief and recovery efforts and local food banks will also need support. Organizations that cater to particularly at-risk populations — like homeless shelters and other social services — would also benefit from support.