Seven children are dead and more than 60 people have been injured after a classroom collapsed in Nairobi on Monday. 

According to officials, rescue workers arrived at the tragic scene to sift through the metal and concrete left behind of the Precious Talent Academy in Kenya’s capital. However, BBC reported rescuers experienced trouble getting to the site due to massive crowds gathering nearby. 

KTN Kenya tweeted that 850 students were at the school when the event took place. 

“There have been 57 students that have been taken to the hospital for treatment, and we can also confirm that there have been seven fatalities,” Cyrus Oguna, a government spokesman, said. 

NTV Kenya reported the first floor of the school collapsed, trapping its victims below in the rubble. Precious Talent Academy Director Moses Ndirangu said he blamed the collapse on the construction of a sewer nearby that weakened the building’s foundations. 

Authorities reportedly cautioned at least 30,000 buildings in Nairobi that were built without approval, were at risk of demise, HuffPost reported. Officials also said the building could not sustain the capacity of students at the Nairobi school. 

“I had just dropped my son to school and heard screams on my way back,” Margaret Muthoni, mother of one of the injured victims, told the AFP news agency. “I am just lucky my son survived.”

Locals in Nairobi are frustrated by the slow emergency response to the incident.

Government officials said it has opened an investigation looking into the cause of the collapse. 

Over the past three years, Kenya has experienced numerous building collapses. In 2016, a six-story residential building in Nairobi caved in after torrential rain, killing 51 people.

In June 2018, at least three people were killed when a building gave away in a residential area of the nation's capital.

"A decision has been made that some of them [hazardous buildings] will be knocked down straight away," Pius Maasai, the police department's head of disaster management, said

There is no word on whether efforts have been made to demolish the at-risk constructions.