More than 72 hours after a massive earthquake left thousands in Port-au-Prince scrambling to find food, water, and loved ones, World Relief’s Stephen Bauman posted on his Twitter account Friday morning from Haiti’s capital city: “No visible aid from outside yet.”

A few hours later, U.S. troops began handing out food and water to desperate victims, four days after many had their last access to either. The aid effort remained massively mired by Friday afternoon, with aid groups reporting their struggle to deliver planeloads of critical supplies.

An airport quagmire left relief planes circling Port-au -Prince on Thursday, with airport officials reporting too little space for landing and too little fuel for re-supplying. A Samaritan’s Purse flight joined the list of planes turned back, with some sent to land in the nearby Turks and Caicos islands for the night. U.S. officials expressed concern about air-dropping relief supplies, fearing such drops would create riots.

The chaos also has left many donors wondering about the best way to assist and which groups to support from afar. “Just because they have name recognition does not mean they’re best able to respond to the disaster,” said Saundra Schimmelpfennig, an aid coordinator in Thailand following the 2004 Indian Ocean tsunami. “Look for organizations operating in the country before the disaster. They will be better able to respond quicker and know the local culture, politics, and needs better.” Schimmelpfennig is updating aid advice on her blog, Good Intentions Are Not Enough.

Ministry Watch also warns on its website MinistryWatch.com, “When disaster hits, scammers take advantage. Do not become a victim, but identify the most worthy ministries so those in true need are helped and not robbed a second time by fraudulent schemes or even well meaning, but inefficient charities.”

The reality is, extreme disasters are big money for relief and other organizations. As of Thursday afternoon the American Red Cross had raised $5 million through a text-messaging campaign for Haiti. It’s important to know, experts say, that the giving will get where it needs to go.

Meanwhile, Haitians are waiting for a wide-scale effort that is the only hope of survival for many. In most parts of the country they also desperately await large-scale equipment like earthmovers and bulldozers that are the only hope for reaching still-buried or injured survivors. For that, U.S. military and other government assistance is needed. For other relief operations, the most immediately effective efforts hinged on groups already in the country. Here’s a look at some organizations’ progress:

The American Bible Society(ABS) is partnering with three groups already in Haiti to distribute aid: the Haitian Bible Society, Operation Compassion, and Water Missions International. ABS staffers in New York City made first contact with Haitian Bible Society president Magda Victor in Port-au-Prince on Friday. Victor reported her home was destroyed, but she was working with local staff to mobilize. ABS workers plan to help distribute 50,000 gallons of drinking water and water purification systems, but no word was immediately available for relief distributed so far.

The American Red Cross(ARC) maintains a regular staff of 15 people in Port-au-Prince. About a dozen outside specialists have joined the small crew to undertake a massive task: figuring out how to distribute aid when large-scale supplies finally arrive. ARC spokeswoman Christie Harlan said workers immediately distributed pre-positioned supplies for about 5,000 people, and planned to fly in another 40 tons as soon as possible.

Children's Hunger Fund (CHF) is wiring $20,000 to relief workers already on the ground in Haiti. The money will go toward food supplies, travel expenses, and helping to set up food centers for more long-term relief. CHF is working with Esperanza International, a mercy network of churches in both Haiti and the Dominican Republic, and just received word that the Esperanza International teams were not yet able to successfully distribute food to the Haitian churches. The teams will focus on providing more long-term assistance by setting up food centers, and will coordinate assistance through Dominican border towns.

Rescue workers had to pull one Christian Aid (U.K.) staff member, Prospery Raymond, from the rubble when the Christian Aid office collapsed in the earthquake. He and two other staff members have gone on to partner with five local organizations to distribute relief. In a January 15 update on its website, Christian Aid said it will give £100,000 for immediate emergency relief and more later. The organization said while it is “very challenging” to get aid into the country and distribute it, additional staff are bringing supplies to Haiti through the Dominican Republic.

Christian Aid Ministries (CAM) has had staff in Haiti for 20 years, so the organization was able to organize a quick response. The staff is operating a clinic out of a house, administering medicine, while the organization in Berlin, Ohio, organizes more medical shipments to Haiti. CAM fed and sheltered about 170 mothers and children at its base northwest of Port-au-Prince and has a rapid-response team on the ground now.

Food for the Hungry (FH) is working with Samaritan's Purse to distribute water filtration systems, water purification tablets, kitchen kits, medical supplies, hygiene kits, and temporary shelter. FH has not received word on whether its supplies have reached Haitians in need. Its Emergency Response Unit has contacted FH staff already present in Haiti, who will help assess community needs.

Medical Teams International(MTI) received word that its team of six—two doctors, three nurses, and the vice president of international relief—has safely landed in an airport north of Port-au-Prince. MTI is working with Global Relief Alliance and has received word that other organizations involved have successfully begun to distribute food and water. A second medical team is due to arrive Sunday night or Monday morning.

Though Samaritan’s Purseflights were re-routed on Thursday, a medical team successfully arrived the day before, bringing medical and hygiene supplies. Dr. David Gette is heading the team’s efforts to assist Baptist Mission Hospital, located outside the city. The 100-bed hospital is lined with hundreds seeking medical attention, and doctors are concentrating on the most critically injured. Samaritan’s Purse planned to re-try humanitarian flights on Friday.

World Relief’s Stephen Bauman’s Twitter account offered hourly updates on the group’s in-country efforts all day on Friday: “World Relief is providing medical care to hundreds today.” “We are organizing feeding centers to communities thru local churches. We will feed several hundred today.” “We were able to secure potable water for several hundred.”

Bauman’s updates also contained grim reports: “Local majors office in charge of removing bodies from streets. Some progress in last 10 hrs.” “Families have wrapped bodies of loved ones, many children and put them on streets for pickup. Gut wrenching.”

World Vision offices in Port-au-Prince suffered heavy damage in the quake, but workers began distributing aid on Wednesday. The group delivered to hospitals their on-hand supplies, including syringes, antibiotics, and bandages. The group planned to bring in more supplies from Denver and Panama as soon as flights allowed.

—With reporting by Mindy Belz and Alisa Harris