"We're at the hospital in New Zealand so I just wanted to let you know if you don't hear from me, we're fine. But my hands are burned so I can't use my phone," Matthew Urey said in the message, according to CNN.
Barbara Barham, Lauren Urey's mother, said she got a call from the cruise company Royal Caribbean asking her if she had heard anything from her daughter after Monday's eruption of an undersea volcano, The Associated Press reported.
After those calls, both the Urey and Barham families said they have received no information on their children's conditions, according to the AP.
WTVR reported Matthew Urey had burns to 80% of his body according to family members. Lauren had burns to 25% of her body, the television station reported.
At least six people were killed, and eight were considered missing, CNN reported. The number of deaths is expected to rise with 31 people still in the hospital. Three people have been treated and released.