Search underway for Sudiksha Konanki, the University of Pittsburgh student who disappeared during Dominican Republic spring break trip

The search for a missing University of Pittsburgh student who disappeared last week while on a spring break trip to the Dominican Republic entered its fourth day on Monday. Authorities are searching by land, air and water for 20-year-old Sudiksha Konanki.

The pre-med student was last seen on video surveillance footage on Thursday, March 6, entering the beach at a hotel in Punta Cana before dawn, where she was staying with five other friends, according to Dominican Republic National Police.

Here’s what we know.

The preliminary timeline of Sudiksha Konanki’s disappearance

Missing person posters describe Konanki as 5 feet, 3 inches tall, with black hair and brown eyes. She was last seen wearing a brown bikini, big round earrings, a metal designer anklet on her right leg, yellow and steel bracelets on her right hand and a multicolored beaded bracelet on her left hand.

March 3: Konanki arrived in the Dominican Republic with five friends. They were all staying at the Hotel Riu Republica in Punta Cana.

March 5: Konanki told her friends that she was going to a party at the resort, her father told CNN.

March 6:

• 4:15 a.m. local time: Konanki and her friends were seen on video surveillance footage entering the beach area of the resort, police said.

• Around 6 a.m.: Surveillance cameras captured five women and one man leaving the beach. Konanki is believed to have stayed behind with a young man, CNN reported, citing a local police source.

• 9:55 a.m.: That same police source said the man was leaving the beach, with no apparent sign of Konanki.

• 4 p.m.: Konanki’s friends reported her missing, since it had been 12 hours since she was last seen, the Riu hotel chain said in a statement. The sheriff’s office in Loudoun County, Va., where she and her family live, was notified of Konanki’s disappearance.

March 7: Police in the Dominican Republic learned of her disappearance after 8 a.m. in a call from the U.S. Embassy in Santo Domingo.

Dominican police lead investigation, with help from U.S.

The Loudoun County Sheriff's Office said in a statement on Sunday that it is working closely with authorities from the State Department, FBI, DEA, Homeland Security Investigations and the University of Pittsburgh police "in support of the ongoing investigation by the Dominican National Police."

Konanki is a citizen of India and a permanent resident of the United States, and the Indian Embassy in the Dominican Republic is helping in the investigation.

The hotel where Konanki is staying is also supporting the search efforts. "From the moment her absence was reported, we have been working closely with the local authorities, including the police and the navy, to conduct a thorough search," the hotel said. "We would like to express our deepest sympathy to the family and friends during this incredibly difficult time. … We are fully committed to doing everything in our power to assist in this situation."

Interviews authorities have conducted so far

The public prosecutor’s office is interviewing Konanki’s friends, NBC News reported. The young man believed to have been on the beach with Konanki on early March 6 has been interviewed by authorities to discuss what happened when the two were allegedly alone and to corroborate his story.

Loudoun County Sheriff Michael Chapman said authorities are combing through security footage and cellphone data for any sign of Konanki.

"We have certainly experts here within the U.S. that will look into all aspects of her phone, her friends' phones, anybody that she might have been with, to see exactly what may have happened there," Chapman said.