At least 36 people died when a “ramshackle” and overcrowded private bus plunged 50 metres down a gorge in Uttarakhand on Monday morning, with top officials blaming the tragedy on transport officials’ failure to check the vehicle for roadworthiness.

Nineteen injured people have been admitted to various hospitals, with nine said to be critical. Five passengers who were thrown out of the window as the bus fell suffered minor injuries.

The casualty count suggests that the 42-seat bus, owned by the Garhwal Motor Owners’ Union Ltd, was carrying at least 53 passengers apart from the driver (dead) and conductor (injured).

Officials suspect a possible brake failure. An unidentified passenger has been quoted as telling the rescuers that he heard a “crack” just before the accident, with the driver crying out that he had lost control over the steering.

Sources said that chief minister Pushkar Singh Dhami, who cut short a Delhi trip and returned after the accident, had suspended the assistant regional transport officers of Paudi and Almora and ordered a magisterial inquiry.

The overnight bus had left Nainidanda in Pauri Garhwal for Ramnagar, a town 250km away in Nainital district. The accident took place near Kupela village in the Marchula area of Almora, 35km from Ramnagar, around 8.30am.

The spot, known locally as the Sharat Bend, lies along a 200-metre stretch of hill road punctuated by sharp turns. Local people said it witnessed a “big accident five or six years ago” and a “small accident” three months ago.

An administrative officer in Ramnagar, speaking off the record, said: “The (bus) owners initially told us there were 44 people on board. But as we counted the bodies and the injured, we realised this was a lie.”

The Ramnagar officer added: “The bus is more than 10 years old and in a ramshackle condition. It should have been prevented from plying on the roads.”

Uttarakhand director-general of police Abhinav Kumar said in the afternoon that the police and the state disaster response force were still at the site, searching for more bodies and injured people, if any.

Sources said six of the injured had been airlifted and admitted to the All India Institute of Medical Sciences (AIIMS), Rishikesh, and four to the Susheela Tiwari Government Hospital, Haldwani. The rest are at the Ramnagar Government Hospital.

Kumar added that initial reports suggested the bus was unfit for use.

“There are some accident hotspots in the state, and we try to hold meetings with officials from various departments at regular intervals to try and avert accidents there,” he said.

“I have asked the department (police) to collect every detail about the big road accidents that took place in the state in the last three years and analyse them so that we can prevent such tragedies.”

Chief minister Dhami met the injured in Ramnagar and said the accident could have been averted had transport officials been alert.

“We have ordered a magisterial inquiry and the guilty will be punished. Our priority at the moment is to save the lives of the injured,” he said.

“Some doctors from AIIMS (Rishikesh) have been sent to Ramnagar to help the doctors there.”

Dhami confirmed 36 deaths and announced ₹4 lakh each for the bereaved families and ₹1 lakh each for the injured. The central government has announced ₹2 lakh each for the families of the dead and ₹50,000 per injured.