(CNN)Four people died, including two children, after a boat capsized in French waters while trying to reach the UK on Tuesday.
The boat was carrying migrants from Dunkirk, in the Nord department on the coast of northern France near Calais, the French Regional Rescue and Surveillance Operational Center said in a statement on Tuesday.
Gaëtan Genel, a communications officer for the Nord department authorities, told CNN on Wednesday that there were four victims: one adult man, one adult woman, and two children aged five and eight years old.
Fifteen people were taken to hospital in Calais and Dunkirk with one man in a condition of "absolute urgency," according to Genel.
Nord maritime authorities said in a separate statement that when the Regional Rescue and Surveillance Operational Center learned of the boat in difficulty they "immediately engaged a number of methods to bring assistance," including a Dunkirk pilot boat and a Belgian army Caïman helicopter.
"One migrant was recovered in the sea by the Belgian army helicopter after becoming separated from the boat due to particularly difficult weather conditions," the maritime authorities said.
The search stopped at 6 p.m. local time as night fell. The authorities said they warned prospective migrants who wished to cross the channel that weather conditions "are often difficult and consequently dangerous to human life."
The prosecutor in Dunkirk has launched an inquiry into the deaths.
French Deputy Minister Marlene Schiappa expressed her sympathies on Tuesday.
"We learned with great sadness the sinking of a boat transporting 19 migrants to England. Despite the full involvements of state resources in the rescue operation, the death toll is heavy and still unclear," Schiappa said on Twitter.
British Prime Minister Boris Johnson offered support to French authorities as they continued to investigate the incident and vowed to "crack down" on those who coordinate the journey.
"[We] will do all we can to crack down on the ruthless criminal gangs who prey on vulnerable people by facilitating these dangerous journey," he said.
The message was also echoed by UK Home Secretary Priti Patel who said she was "truly saddened to learn of the tragic loss of life" in the Channel.
"This tragic news highlights the dangers that come with crossing the channel and I will do everything I can to stop callous criminals exploiting vulnerable people," Patel said in a statement.
UK refugee charity Care for Calais said it was "utterly devastated" by the news of the fatalities, remarking that "this unnecessary loss of life has to stop."
"This loss of life should be a wake-up call for those in power in Fra